diff --git a/.version b/.version
index f2f3fcc..48cf2f2 100644
--- a/.version
+++ b/.version
@@ -1 +1 @@
-11.3
\ No newline at end of file
+11.5
\ No newline at end of file
diff --git a/HISTORY b/HISTORY
index ad7411f..65a6d9c 100644
--- a/HISTORY
+++ b/HISTORY
@@ -1,6 +1,20 @@
 SnapRAID HISTORY
 ================
 
+11.5 2020/05
+============
+ * Removed the default -march=native to allow to deploy in any machine.
+ * Fixed typos [Andrea Gelmini]
+
+11.4 2020/05
+============
+ * Fix build errors due new gcc 10 default for -fno-common.
+ * In fixing, if a parity is filtered out, don't attempt to recover its size,
+   and proceed without it if missing.
+ * Avoid unnecessary parity read when fixing the parity itself.
+   This improves the 'fix' speed when a parity file is completely missing.
+ * Removed a build warning about major/minor defined now in sys/sysmacros.h.
+
 11.3 2018/11
 ============
  * Fixed handing of Linux devices that have multiple slaves. This affects
@@ -139,7 +153,7 @@ SnapRAID HISTORY
    A workaround was to just run 'sync' one time with the -N,
    --force-nocopy option to disable the copy detection.
  * Restored the -O2 optimization option for Windows binaries, as -Og has
-   a too big performance penality.
+   a too big performance penalty.
 
 9.2 2016/01
 ===========
@@ -412,7 +426,7 @@ SnapRAID HISTORY
    and Opteron.
  * Faster RAID5 and RAID6 implementation for ARM 64 bit CPUs.
  * If a silent error is found during a "sync" command, directly marks
-   the block as bad like in "scrub", without stopping the the "sync"
+   the block as bad like in "scrub", without stopping the "sync"
    process.
  * Sort files by inode when listing the directory. This improves
    the scanning performance.
diff --git a/Makefile.am b/Makefile.am
index 4c0c167..447d96b 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -83,6 +83,7 @@ noinst_HEADERS = \
 	cmdline/murmur3test.c \
 	cmdline/spooky2.c \
 	cmdline/spooky2test.c \
+	cmdline/metro.c \
 	cmdline/fnmatch.h \
 	cmdline/import.h \
 	cmdline/search.h \
@@ -158,7 +159,7 @@ maintainer-clean-local:
 CHECKFLAGS_COMMON = --test-skip-device --test-skip-self --test-force-progress --no-warnings --test-parity-limit=3333333
 
 # --test-force-order-alpha
-# Ensures to process files always in the same order despites
+# Ensures to process files always in the same order despite
 # the inode, physical location, and dir order assigned by the OS.
 CHECKFLAGS_ALPHA = $(CHECKFLAGS_COMMON) --test-force-order-alpha
 
@@ -499,7 +500,7 @@ endif
 	$(FAILENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(CONF) --test-run "rm bench/disk1/RUN-RM" --test-expect-failure sync
 	echo RUN > bench/disk1/RUN-CHMOD
 if HAVE_POSIX
-# Doesn't run this test as root because the root user overrride permissions
+# Doesn't run this test as root because the root user override permissions
 	if [[ $$EUID -ne 0 ]]; then \
 		$(FAILENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(CONF) --test-run "chmod a-r bench/disk1/RUN-CHMOD" --test-expect-failure sync; \
 	fi
diff --git a/Makefile.in b/Makefile.in
index 73f8ac5..9524fd5 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -429,6 +429,7 @@ noinst_HEADERS = \
 	cmdline/murmur3test.c \
 	cmdline/spooky2.c \
 	cmdline/spooky2test.c \
+	cmdline/metro.c \
 	cmdline/fnmatch.h \
 	cmdline/import.h \
 	cmdline/search.h \
@@ -487,7 +488,7 @@ man_MANS = snapraid.1
 CHECKFLAGS_COMMON = --test-skip-device --test-skip-self --test-force-progress --no-warnings --test-parity-limit=3333333
 
 # --test-force-order-alpha
-# Ensures to process files always in the same order despites
+# Ensures to process files always in the same order despite
 # the inode, physical location, and dir order assigned by the OS.
 CHECKFLAGS_ALPHA = $(CHECKFLAGS_COMMON) --test-force-order-alpha
 
@@ -1409,7 +1410,7 @@ check-local:
 @HAVE_THREAD_CHECKER_FALSE@	echo RUN > bench/disk1/RUN-RM
 @HAVE_THREAD_CHECKER_FALSE@	$(FAILENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(CONF) --test-run "rm bench/disk1/RUN-RM" --test-expect-failure sync
 @HAVE_THREAD_CHECKER_FALSE@	echo RUN > bench/disk1/RUN-CHMOD
-# Doesn't run this test as root because the root user overrride permissions
+# Doesn't run this test as root because the root user override permissions
 @HAVE_POSIX_TRUE@@HAVE_THREAD_CHECKER_FALSE@	if [[ $$EUID -ne 0 ]]; then \
 @HAVE_POSIX_TRUE@@HAVE_THREAD_CHECKER_FALSE@		$(FAILENV) ./snapraid$(EXEEXT) $(CHECKFLAGS) -c $(CONF) --test-run "chmod a-r bench/disk1/RUN-CHMOD" --test-expect-failure sync; \
 @HAVE_POSIX_TRUE@@HAVE_THREAD_CHECKER_FALSE@	fi
diff --git a/README b/README
index 52a90b7..9033002 100644
--- a/README
+++ b/README
@@ -11,6 +11,8 @@ have a lot of big files that rarely change.
 Beside the ability to recover from disk failures, the other
 features of SnapRAID are:
 
+* You can use disk already filled with files, without the need to
+  reformat them. You will access them like now.
 * All your data is hashed to ensure data integrity and to avoid
   silent corruption.
 * If the failed disks are too many to allow a recovery,
@@ -18,12 +20,11 @@ features of SnapRAID are:
   All the data in the other disks is safe.
 * If you accidentally delete some files in a disk, you can
   recover them.
-* You can start with already filled disks.
 * The disks can have different sizes.
 * You can add disks at any time.
 * It doesn't lock-in your data. You can stop using SnapRAID at any
   time without the need to reformat or move data.
-* To access a file, a single disk needs to spin, saving power and
+* To access a file, only a single disk needs to spin, saving power and
   producing less noise.
 
 The official site of SnapRAID is:
diff --git a/TODO b/TODO
index f02c44c..329b417 100644
--- a/TODO
+++ b/TODO
@@ -25,8 +25,8 @@ with a mono thread implementation with 100.0000 files.
 * Support more parity levels
 It can be done with a generic computation function, using
 intrinsic for SSSE3 and AVX instructions.
-It would be intersting to compare performance with the hand-written
-assembler functions. Eventially we can convert them to use intrinsic also.
+It would be interesting to compare performance with the hand-written
+assembler functions. Eventually we can convert them to use intrinsic also.
 https://sourceforge.net/p/snapraid/discussion/1677233/thread/9dbd7581/
 
 * Extend haspdeep to support the SnapRAID hash :
@@ -151,7 +151,7 @@ See: https://sourceforge.net/p/snapraid/discussion/1677233/thread/cdea773f/
 * Allocate parity minimizing concurrent use of it
 Each parity allocation should check for a parity
 range with less utilization by other disks.
-We need to take care do disable this meachnism when the parity space
+We need to take care do disable this mechanism when the parity space
 is near to fillup the parity partition.
 See: https://sourceforge.net/p/snapraid/discussion/1677233/thread/1797bf7d/
 + This increase the possibility of recovering with multiple failures with not
@@ -182,7 +182,7 @@ allowing the user to choose where to put it.
 - It won't work with disks of different size.
 Suppose to have all disks of size N, with only one of size M>N.
 To fully use the M space, you can allocate a full N parity in such disk,
-but the remaning space will also need additional parity in the other disks,
+but the remaining space will also need additional parity in the other disks,
 in fact requiring a total of M parity for the array.
 In the end, we cannot avoid that the first biggest disk added is fully
 dedicated to parity, even if it means to leave some space unused.
@@ -199,7 +199,7 @@ But it should be only few bits for each file. So, it should be manageable.
 A lot of discussions about this feature :)
 https://sourceforge.net/p/snapraid/discussion/1677233/thread/b2cd9385/
 - The only benefit is to distribute better the data. This could help the recovery process,
-in case of multiple failures. But no real usability or funtionality benefit in the normal
+in case of multiple failures. But no real usability or functionality benefit in the normal
 case.
 
 * https://sourceforge.net/p/snapraid/discussion/1677233/thread/2cb97e8a/
@@ -229,7 +229,7 @@ are automatically deleted.
 
 * Checks if splitting hash/parity computation in 4K pages
 can improve speed in sync. That should increase cache locality,
-because we read the data two times for hash and and parity,
+because we read the data two times for hash and parity,
 and if we manage to keep it in the cache, we should save time.
 - We now hash first the faster disks, and this could
 reduce performance as we'll have to wait for all disks.
diff --git a/acinclude.m4 b/acinclude.m4
index 1b92cc9..96e9c5f 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -1,7 +1,7 @@
 dnl @synopsis AC_CHECK_CC_OPT(flag, ifyes, ifno)
 dnl 
-dnl Shows a message as like "checking wether gcc accepts flag ... no"
-dnl and executess ifyes or ifno.
+dnl Shows a message as like "checking whether gcc accepts flag ... no"
+dnl and executes ifyes or ifno.
 
 AC_DEFUN([AC_CHECK_CC_OPT],
 [
diff --git a/cmdline/check.c b/cmdline/check.c
index 72012df..b3d2048 100644
--- a/cmdline/check.c
+++ b/cmdline/check.c
@@ -574,7 +574,7 @@ static int repair(struct snapraid_state* state, int rehash, unsigned pos, unsign
 	} else {
 		log_tag("recover_unsync:%u:%u: Skipped for%s%s\n", pos, n,
 			!something_to_recover ? " nothing to recover" : "",
-			!something_unsynced ? " nothing unsynched" : ""
+			!something_unsynced ? " nothing unsynced" : ""
 		);
 	}
 
@@ -1441,7 +1441,7 @@ static int state_check_process(struct snapraid_state* state, int fix, struct sna
 			char path[PATH_MAX];
 			struct stat st;
 			struct snapraid_file* file;
-			int unsuccesful = 0;
+			int unsuccessful = 0;
 
 			file = node->data;
 			node = node->next; /* next node */
@@ -1460,24 +1460,24 @@ static int state_check_process(struct snapraid_state* state, int fix, struct sna
 			pathprint(path, sizeof(path), "%s%s", disk->dir, file->sub);
 			ret = stat(path, &st);
 			if (ret == -1) {
-				unsuccesful = 1;
+				unsuccessful = 1;
 
 				log_error("Error stating empty file '%s'. %s.\n", path, strerror(errno));
 				log_tag("error:%s:%s: Empty file stat error\n", disk->name, esc_tag(file->sub, esc_buffer));
 				++error;
 			} else if (!S_ISREG(st.st_mode)) {
-				unsuccesful = 1;
+				unsuccessful = 1;
 
 				log_tag("error:%s:%s: Empty file error for not regular file\n", disk->name, esc_tag(file->sub, esc_buffer));
 				++error;
 			} else if (st.st_size != 0) {
-				unsuccesful = 1;
+				unsuccessful = 1;
 
 				log_tag("error:%s:%s: Empty file error for size '%" PRIu64 "'\n", disk->name, esc_tag(file->sub, esc_buffer), (uint64_t)st.st_size);
 				++error;
 			}
 
-			if (fix && unsuccesful) {
+			if (fix && unsuccessful) {
 				int f;
 
 				/* create the ancestor directories */
@@ -1552,7 +1552,7 @@ static int state_check_process(struct snapraid_state* state, int fix, struct sna
 			struct stat st;
 			struct stat stto;
 			struct snapraid_link* slink;
-			int unsuccesful = 0;
+			int unsuccessful = 0;
 			int unrecoverable = 0;
 
 			slink = node->data;
@@ -1568,13 +1568,13 @@ static int state_check_process(struct snapraid_state* state, int fix, struct sna
 				pathprint(path, sizeof(path), "%s%s", disk->dir, slink->sub);
 				ret = stat(path, &st);
 				if (ret == -1) {
-					unsuccesful = 1;
+					unsuccessful = 1;
 
 					log_error("Error stating hardlink '%s'. %s.\n", path, strerror(errno));
 					log_tag("hardlink_error:%s:%s:%s: Hardlink stat error\n", disk->name, esc_tag(slink->sub, esc_buffer), esc_tag(slink->linkto, esc_buffer_alt));
 					++error;
 				} else if (!S_ISREG(st.st_mode)) {
-					unsuccesful = 1;
+					unsuccessful = 1;
 
 					log_tag("hardlink_error:%s:%s:%s: Hardlink error for not regular file\n", disk->name, esc_tag(slink->sub, esc_buffer), esc_tag(slink->linkto, esc_buffer_alt));
 					++error;
@@ -1584,7 +1584,7 @@ static int state_check_process(struct snapraid_state* state, int fix, struct sna
 				pathprint(pathto, sizeof(pathto), "%s%s", disk->dir, slink->linkto);
 				ret = stat(pathto, &stto);
 				if (ret == -1) {
-					unsuccesful = 1;
+					unsuccessful = 1;
 
 					if (errno == ENOENT) {
 						unrecoverable = 1;
@@ -1604,12 +1604,12 @@ static int state_check_process(struct snapraid_state* state, int fix, struct sna
 					log_tag("hardlink_error:%s:%s:%s: Hardlink to stat error\n", disk->name, esc_tag(slink->sub, esc_buffer), esc_tag(slink->linkto, esc_buffer_alt));
 					++error;
 				} else if (!S_ISREG(stto.st_mode)) {
-					unsuccesful = 1;
+					unsuccessful = 1;
 
 					log_tag("hardlink_error:%s:%s:%s: Hardlink-to error for not regular file\n", disk->name, esc_tag(slink->sub, esc_buffer), esc_tag(slink->linkto, esc_buffer_alt));
 					++error;
-				} else if (!unsuccesful && st.st_ino != stto.st_ino) {
-					unsuccesful = 1;
+				} else if (!unsuccessful && st.st_ino != stto.st_ino) {
+					unsuccessful = 1;
 
 					log_error("Mismatch hardlink '%s' and '%s'. Different inode.\n", path, pathto);
 					log_tag("hardlink_error:%s:%s:%s: Hardlink mismatch for different inode\n", disk->name, esc_tag(slink->sub, esc_buffer), esc_tag(slink->linkto, esc_buffer_alt));
@@ -1620,13 +1620,13 @@ static int state_check_process(struct snapraid_state* state, int fix, struct sna
 				pathprint(path, sizeof(path), "%s%s", disk->dir, slink->sub);
 				ret = readlink(path, linkto, sizeof(linkto));
 				if (ret < 0) {
-					unsuccesful = 1;
+					unsuccessful = 1;
 
 					log_error("Error reading symlink '%s'. %s.\n", path, strerror(errno));
 					log_tag("symlink_error:%s:%s: Symlink read error\n", disk->name, esc_tag(slink->sub, esc_buffer));
 					++error;
 				} else if (ret >= PATH_MAX) {
-					unsuccesful = 1;
+					unsuccessful = 1;
 
 					log_error("Error reading symlink '%s'. Symlink too long.\n", path);
 					log_tag("symlink_error:%s:%s: Symlink read error\n", disk->name, esc_tag(slink->sub, esc_buffer));
@@ -1635,7 +1635,7 @@ static int state_check_process(struct snapraid_state* state, int fix, struct sna
 					linkto[ret] = 0;
 
 					if (strcmp(linkto, slink->linkto) != 0) {
-						unsuccesful = 1;
+						unsuccessful = 1;
 
 						log_tag("symlink_error:%s:%s: Symlink data error '%s' instead of '%s'\n", disk->name, esc_tag(slink->sub, esc_buffer), linkto, slink->linkto);
 						++error;
@@ -1643,7 +1643,7 @@ static int state_check_process(struct snapraid_state* state, int fix, struct sna
 				}
 			}
 
-			if (fix && unsuccesful && !unrecoverable) {
+			if (fix && unsuccessful && !unrecoverable) {
 				/* create the ancestor directories */
 				ret = mkancestor(path);
 				if (ret != 0) {
@@ -1720,7 +1720,7 @@ static int state_check_process(struct snapraid_state* state, int fix, struct sna
 			char path[PATH_MAX];
 			struct stat st;
 			struct snapraid_dir* dir;
-			int unsuccesful = 0;
+			int unsuccessful = 0;
 
 			dir = node->data;
 			node = node->next; /* next node */
@@ -1734,19 +1734,19 @@ static int state_check_process(struct snapraid_state* state, int fix, struct sna
 			pathprint(path, sizeof(path), "%s%s", disk->dir, dir->sub);
 			ret = stat(path, &st);
 			if (ret == -1) {
-				unsuccesful = 1;
+				unsuccessful = 1;
 
 				log_error("Error stating dir '%s'. %s.\n", path, strerror(errno));
 				log_tag("dir_error:%s:%s: Dir stat error\n", disk->name, esc_tag(dir->sub, esc_buffer));
 				++error;
 			} else if (!S_ISDIR(st.st_mode)) {
-				unsuccesful = 1;
+				unsuccessful = 1;
 
 				log_tag("dir_error:%s:%s: Dir error for not directory\n", disk->name, esc_tag(dir->sub, esc_buffer));
 				++error;
 			}
 
-			if (fix && unsuccesful) {
+			if (fix && unsuccessful) {
 				/* create the ancestor directories */
 				ret = mkancestor(path);
 				if (ret != 0) {
@@ -1973,20 +1973,32 @@ int state_check(struct snapraid_state* state, int fix, block_off_t blockstart, b
 			}
 
 			parity_ptr[l] = &parity[l];
-			ret = parity_create(parity_ptr[l], &state->parity[l], l, state->file_mode, state->block_size, state->opt.parity_limit_size);
-			if (ret == -1) {
-				/* LCOV_EXCL_START */
-				log_fatal("WARNING! Without an accessible %s file, it isn't possible to fix any error.\n", lev_name(l));
-				exit(EXIT_FAILURE);
-				/* LCOV_EXCL_STOP */
-			}
 
-			ret = parity_chsize(parity_ptr[l], &state->parity[l], 0, size, state->block_size, state->opt.skip_fallocate, state->opt.skip_space_holder);
-			if (ret == -1) {
-				/* LCOV_EXCL_START */
-				log_fatal("WARNING! Without an accessible %s file, it isn't possible to sync.\n", lev_name(l));
-				exit(EXIT_FAILURE);
-				/* LCOV_EXCL_STOP */
+			/* if the parity is excluded */
+			if (state->parity[l].is_excluded_by_filter) {
+				/* open for reading, and ignore error */
+				ret = parity_open(parity_ptr[l], &state->parity[l], l, state->file_mode, state->block_size, state->opt.parity_limit_size);
+				if (ret == -1) {
+					/* continue anyway */
+					parity_ptr[l] = 0;
+				}
+			} else {
+				/* open for writing */
+				ret = parity_create(parity_ptr[l], &state->parity[l], l, state->file_mode, state->block_size, state->opt.parity_limit_size);
+				if (ret == -1) {
+					/* LCOV_EXCL_START */
+					log_fatal("WARNING! Without an accessible %s file, it isn't possible to fix any error.\n", lev_name(l));
+					exit(EXIT_FAILURE);
+					/* LCOV_EXCL_STOP */
+				}
+
+				ret = parity_chsize(parity_ptr[l], &state->parity[l], 0, size, state->block_size, state->opt.skip_fallocate, state->opt.skip_space_holder);
+				if (ret == -1) {
+					/* LCOV_EXCL_START */
+					log_fatal("WARNING! Without an accessible %s file, it isn't possible to sync.\n", lev_name(l));
+					exit(EXIT_FAILURE);
+					/* LCOV_EXCL_STOP */
+				}
 			}
 		}
 	} else if (!state->opt.auditonly) {
@@ -2030,14 +2042,26 @@ int state_check(struct snapraid_state* state, int fix, block_off_t blockstart, b
 	/* try to close only if opened */
 	for (l = 0; l < state->level; ++l) {
 		if (parity_ptr[l]) {
+			/* if fixing and not excluded, truncate parity not valid */
+			if (fix && !state->parity[l].is_excluded_by_filter) {
+				ret = parity_truncate(parity_ptr[l]);
+				if (ret == -1) {
+					/* LCOV_EXCL_START */
+					log_fatal("DANGER! Unexpected truncate error in %s disk.\n", lev_name(l));
+					++error;
+					/* continue, as we are already exiting */
+					/* LCOV_EXCL_STOP */
+				}
+			}
+
 			ret = parity_close(parity_ptr[l]);
-			/* LCOV_EXCL_START */
 			if (ret == -1) {
+				/* LCOV_EXCL_START */
 				log_fatal("DANGER! Unexpected close error in %s disk.\n", lev_name(l));
 				++error;
 				/* continue, as we are already exiting */
+				/* LCOV_EXCL_STOP */
 			}
-			/* LCOV_EXCL_STOP */
 		}
 	}
 
diff --git a/cmdline/device.c b/cmdline/device.c
index f170ad6..605fdc3 100644
--- a/cmdline/device.c
+++ b/cmdline/device.c
@@ -818,7 +818,7 @@ static void state_smart(unsigned n, tommy_list* low)
 
 	/*      |<##################################################################72>|####80>| */
 	printf("These values are the probabilities that in the next year you'll have a\n");
-	printf("sequence of failures that the parity WONT be able to recover, assuming\n");
+	printf("sequence of failures that the parity WON'T be able to recover, assuming\n");
 	printf("that you regularly scrub, and in case repair, the array in the specified\n");
 	printf("time.\n");
 
diff --git a/cmdline/elem.h b/cmdline/elem.h
index e821e41..0c4a555 100644
--- a/cmdline/elem.h
+++ b/cmdline/elem.h
@@ -349,7 +349,7 @@ struct snapraid_disk {
 	block_off_t first_free_block;
 
 	int has_volatile_inodes; /**< If the underline file-system has not persistent inodes. */
-	int has_volatile_hardlinks; /**< If the underline file-system has not syncronized metadata for hardlink (NTFS). */
+	int has_volatile_hardlinks; /**< If the underline file-system has not synchronized metadata for hardlink (NTFS). */
 	int has_unreliable_physical; /**< If the physical offset of files has duplicates. */
 	int has_different_uuid; /**< If the disk has a different UUID, meaning that it is not the same file-system. */
 	int has_unsupported_uuid; /**< If the disk doesn't report UUID, meaning it's not supported. */
@@ -1000,7 +1000,7 @@ int fs_check(struct snapraid_disk* disk);
  * After this call you can use the par2file/par2block operations
  * to query the relation.
  *
- * \note This function is NOT thread-safe as it uses the the disk cache. +
+ * \note This function is NOT thread-safe as it uses the disk cache. +
  */
 void fs_allocate(struct snapraid_disk* disk, block_off_t parity_pos, struct snapraid_file* file, block_off_t file_pos);
 
@@ -1010,7 +1010,7 @@ void fs_allocate(struct snapraid_disk* disk, block_off_t parity_pos, struct snap
  * After this call the par2file/par2block operations
  * won't find anymore the parity association.
  *
- * \note This function is NOT thread-safe as it uses the the disk cache.
+ * \note This function is NOT thread-safe as it uses the disk cache.
  */
 void fs_deallocate(struct snapraid_disk* disk, block_off_t pos);
 
@@ -1129,7 +1129,7 @@ static inline snapraid_info info_make(time_t last_access, int error, int rehash,
 /**
  * Extract the time information.
  * This is the last time when the block was know to be correct.
- * The "scrubbed" info tells if the time is referreing at the latest sync or scrub.
+ * The "scrubbed" info tells if the time is referring at the latest sync or scrub.
  */
 static inline time_t info_get_time(snapraid_info info)
 {
diff --git a/cmdline/io.c b/cmdline/io.c
index c71ba41..156d512 100644
--- a/cmdline/io.c
+++ b/cmdline/io.c
@@ -19,6 +19,19 @@
 
 #include "io.h"
 
+void (*io_start)(struct snapraid_io* io,
+	block_off_t blockstart, block_off_t blockmax,
+	int (*block_is_enabled)(void* arg, block_off_t), void* blockarg) = 0;
+void (*io_stop)(struct snapraid_io* io) = 0;
+block_off_t (*io_read_next)(struct snapraid_io* io, void*** buffer) = 0;
+struct snapraid_task* (*io_data_read)(struct snapraid_io* io, unsigned* diskcur, unsigned* waiting_map, unsigned* waiting_mac) = 0;
+struct snapraid_task* (*io_parity_read)(struct snapraid_io* io, unsigned* levcur, unsigned* waiting_map, unsigned* waiting_mac) = 0;
+void (*io_parity_write)(struct snapraid_io* io, unsigned* levcur, unsigned* waiting_map, unsigned* waiting_mac) = 0;
+void (*io_write_preset)(struct snapraid_io* io, block_off_t blockcur, int skip) = 0;
+void (*io_write_next)(struct snapraid_io* io, block_off_t blockcur, int skip, int* writer_error) = 0;
+void (*io_refresh)(struct snapraid_io* io) = 0;
+
+
 /**
  * Get the next block position to process.
  */
diff --git a/cmdline/io.h b/cmdline/io.h
index 82ec744..a0cfb63 100644
--- a/cmdline/io.h
+++ b/cmdline/io.h
@@ -306,21 +306,21 @@ void io_init(struct snapraid_io* io, struct snapraid_state* state,
 	struct snapraid_parity_handle* parity_handle_map, unsigned parity_handle_max);
 
 /**
- * Deinitialize te InputOutput workers.
+ * Deinitialize the InputOutput workers.
  */
 void io_done(struct snapraid_io* io);
 
 /**
  * Start all the worker threads.
  */
-void (*io_start)(struct snapraid_io* io,
+extern void (*io_start)(struct snapraid_io* io,
 	block_off_t blockstart, block_off_t blockmax,
 	int (*block_is_enabled)(void* arg, block_off_t), void* blockarg);
 
 /**
  * Stop all the worker threads.
  */
-void (*io_stop)(struct snapraid_io* io);
+extern void (*io_stop)(struct snapraid_io* io);
 
 /**
  * Next read position.
@@ -332,7 +332,7 @@ void (*io_stop)(struct snapraid_io* io);
  * \param buffer The data buffers to use for this position.
  * \return The parity position.
  */
-block_off_t (*io_read_next)(struct snapraid_io* io, void*** buffer);
+extern block_off_t (*io_read_next)(struct snapraid_io* io, void*** buffer);
 
 /**
  * Read a data block.
@@ -343,7 +343,7 @@ block_off_t (*io_read_next)(struct snapraid_io* io, void*** buffer);
  * \param diskcur The position of the data block in the ::handle_map vector.
  * \return The completed task.
  */
-struct snapraid_task* (*io_data_read)(struct snapraid_io* io, unsigned* diskcur, unsigned* waiting_map, unsigned* waiting_mac);
+extern struct snapraid_task* (*io_data_read)(struct snapraid_io* io, unsigned* diskcur, unsigned* waiting_map, unsigned* waiting_mac);
 
 /**
  * Read a parity block.
@@ -354,7 +354,7 @@ struct snapraid_task* (*io_data_read)(struct snapraid_io* io, unsigned* diskcur,
  * \param levcur The position of the parity block in the ::parity_handle_map vector.
  * \return The completed task.
  */
-struct snapraid_task* (*io_parity_read)(struct snapraid_io* io, unsigned* levcur, unsigned* waiting_map, unsigned* waiting_mac);
+extern struct snapraid_task* (*io_parity_read)(struct snapraid_io* io, unsigned* levcur, unsigned* waiting_map, unsigned* waiting_mac);
 
 /**
  * Write of a parity block.
@@ -364,7 +364,7 @@ struct snapraid_task* (*io_parity_read)(struct snapraid_io* io, unsigned* levcur
  * \param io InputOutput context.
  * \param levcur The position of the parity block in the ::parity_handle_map vector.
  */
-void (*io_parity_write)(struct snapraid_io* io, unsigned* levcur, unsigned* waiting_map, unsigned* waiting_mac);
+extern void (*io_parity_write)(struct snapraid_io* io, unsigned* levcur, unsigned* waiting_map, unsigned* waiting_mac);
 
 /**
  * Preset the write position.
@@ -376,7 +376,7 @@ void (*io_parity_write)(struct snapraid_io* io, unsigned* levcur, unsigned* wait
  * \param blockcur The parity position to write.
  * \param skip Skip the writes, in case parity doesn't need to be updated.
  */
-void (*io_write_preset)(struct snapraid_io* io, block_off_t blockcur, int skip);
+extern void (*io_write_preset)(struct snapraid_io* io, block_off_t blockcur, int skip);
 
 /**
  * Next write position.
@@ -389,12 +389,12 @@ void (*io_write_preset)(struct snapraid_io* io, block_off_t blockcur, int skip);
  * \param skip Skip the writes, in case parity doesn't need to be updated.
  * \param writer_error Return the number of errors. Vector of IO_WRITER_ERROR_MAX elements.
  */
-void (*io_write_next)(struct snapraid_io* io, block_off_t blockcur, int skip, int* writer_error);
+extern void (*io_write_next)(struct snapraid_io* io, block_off_t blockcur, int skip, int* writer_error);
 
 /**
  * Refresh the number of cached blocks for all data and parity disks.
  */
-void (*io_refresh)(struct snapraid_io* io);
+extern void (*io_refresh)(struct snapraid_io* io);
 
 #endif
 
diff --git a/cmdline/metro.c b/cmdline/metro.c
new file mode 100644
index 0000000..18f4027
--- /dev/null
+++ b/cmdline/metro.c
@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) 2019 Andrea Mazzoleni
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * Derivative work from metrohash128.cpp
+ *
+ * metrohash128.cpp
+ *
+ * Copyright 2015-2018 J. Andrew Rogers
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+static const uint64_t k0 = 0xC83A91E1;
+static const uint64_t k1 = 0x8648DBDB;
+static const uint64_t k2 = 0x7BDEC03B;
+static const uint64_t k3 = 0x2F5870A5;
+
+void MetroHash128(const void* data, size_t size, const uint8_t* seed, uint8_t* digest)
+{
+	const uint8_t* ptr = data;
+	uint64_t v[4];
+
+	v[0] = (util_read64(seed) - k0) * k3;
+	v[1] = (util_read64(seed + 8) + k1) * k2;
+
+	if (size >= 32) {
+		v[2] = (util_read64(seed) + k0) * k2;
+		v[3] = (util_read64(seed + 8) - k1) * k3;
+
+		do {
+			v[0] += util_read64(ptr) * k0; ptr += 8; v[0] = util_rotr64(v[0], 29) + v[2];
+			v[1] += util_read64(ptr) * k1; ptr += 8; v[1] = util_rotr64(v[1], 29) + v[3];
+			v[2] += util_read64(ptr) * k2; ptr += 8; v[2] = util_rotr64(v[2], 29) + v[0];
+			v[3] += util_read64(ptr) * k3; ptr += 8; v[3] = util_rotr64(v[3], 29) + v[1];
+			size -= 32;
+		} while (size >= 32);
+
+		v[2] ^= util_rotr64(((v[0] + v[3]) * k0) + v[1], 21) * k1;
+		v[3] ^= util_rotr64(((v[1] + v[2]) * k1) + v[0], 21) * k0;
+		v[0] ^= util_rotr64(((v[0] + v[2]) * k0) + v[3], 21) * k1;
+		v[1] ^= util_rotr64(((v[1] + v[3]) * k1) + v[2], 21) * k0;
+	}
+
+	if (size >= 16) {
+		v[0] += util_read64(ptr) * k2; ptr += 8; v[0] = util_rotr64(v[0], 33) * k3;
+		v[1] += util_read64(ptr) * k2; ptr += 8; v[1] = util_rotr64(v[1], 33) * k3;
+		v[0] ^= util_rotr64((v[0] * k2) + v[1], 45) * k1;
+		v[1] ^= util_rotr64((v[1] * k3) + v[0], 45) * k0;
+		size -= 16;
+	}
+
+	if (size >= 8) {
+		v[0] += util_read64(ptr) * k2; ptr += 8; v[0] = util_rotr64(v[0], 33) * k3;
+		v[0] ^= util_rotr64((v[0] * k2) + v[1], 27) * k1;
+		size -= 8;
+	}
+
+	if (size >= 4) {
+		v[1] += util_read32(ptr) * k2; ptr += 4; v[1] = util_rotr64(v[1], 33) * k3;
+		v[1] ^= util_rotr64((v[1] * k3) + v[0], 46) * k0;
+		size -= 4;
+	}
+
+	if (size >= 2) {
+		v[0] += util_read16(ptr) * k2; ptr += 2; v[0] = util_rotr64(v[0], 33) * k3;
+		v[0] ^= util_rotr64((v[0] * k2) + v[1], 22) * k1;
+		size -= 2;
+	}
+
+	if (size >= 1) {
+		v[1] += util_read8(ptr) * k2; v[1] = util_rotr64(v[1], 33) * k3;
+		v[1] ^= util_rotr64((v[1] * k3) + v[0], 58) * k0;
+	}
+
+	v[0] += util_rotr64((v[0] * k0) + v[1], 13);
+	v[1] += util_rotr64((v[1] * k1) + v[0], 37);
+	v[0] += util_rotr64((v[0] * k2) + v[1], 13);
+	v[1] += util_rotr64((v[1] * k3) + v[0], 37);
+
+	util_write64(digest, v[0]);
+	util_write64(digest + 8, v[0]);
+}
+
diff --git a/cmdline/mingw.c b/cmdline/mingw.c
index ef10ee8..5b8c9d4 100644
--- a/cmdline/mingw.c
+++ b/cmdline/mingw.c
@@ -1556,7 +1556,7 @@ int windows_link(const char* existing, const char* file)
 }
 
 /**
- * In Windows 10 allow creationg of symblink by not priviliged user.
+ * In Windows 10 allow creation of symblink by not privileged user.
  *
  * See: Symlinks in Windows 10!
  * https://blogs.windows.com/buildingapps/2016/12/02/symlinks-windows-10/#cQG7cx48oGH86lkI.97
@@ -1724,7 +1724,7 @@ int fsinfo(const char* path, int* has_persistent_inode, int* has_syncronized_har
 	if (has_persistent_inode)
 		*has_persistent_inode = 1;
 
-	/* NTFS doesn't syncronize hardlinks metadata */
+	/* NTFS doesn't synchronize hardlinks metadata */
 	if (has_syncronized_hardlinks)
 		*has_syncronized_hardlinks = 0;
 
diff --git a/cmdline/parity.c b/cmdline/parity.c
index 6bfdbcd..e4569fe 100644
--- a/cmdline/parity.c
+++ b/cmdline/parity.c
@@ -217,6 +217,9 @@ int parity_create(struct snapraid_parity_handle* handle, const struct snapraid_p
 			/* LCOV_EXCL_STOP */
 		}
 
+		/* the initial valid size is the size on disk */
+		split->valid_size = split->st.st_size;
+
 		/**
 		 * If the parity size is not yet set, set it now.
 		 * This happens when expanding the number of parities,
@@ -528,6 +531,10 @@ static int parity_handle_chsize(struct snapraid_split_handle* split, data_off_t
 		/* LCOV_EXCL_STOP */
 	}
 
+	/* if we shrink, update the valid size, but don't update when growing */
+	if (split->valid_size > split->st.st_size)
+		split->valid_size = split->st.st_size;
+
 	return 0;
 }
 
@@ -697,6 +704,9 @@ int parity_open(struct snapraid_parity_handle* handle, const struct snapraid_par
 			/* LCOV_EXCL_STOP */
 		}
 
+		/* the initial valid size is the size on disk */
+		split->valid_size = split->st.st_size;
+
 		/**
 		 * If the parity size is not yet set, set it now.
 		 * This happens when expanding the number of parities,
@@ -751,7 +761,7 @@ int parity_sync(struct snapraid_parity_handle* handle)
 		ret = fsync(split->f);
 		if (ret != 0) {
 			/* LCOV_EXCL_START */
-			log_fatal("Error synching parity file '%s'. %s.\n", split->path, strerror(errno));
+			log_fatal("Error syncing parity file '%s'. %s.\n", split->path, strerror(errno));
 			return -1;
 			/* LCOV_EXCL_STOP */
 		}
@@ -761,6 +771,30 @@ int parity_sync(struct snapraid_parity_handle* handle)
 	return 0;
 }
 
+int parity_truncate(struct snapraid_parity_handle* handle)
+{
+	unsigned s;
+	int f_ret = 0;
+
+	for (s = 0; s < handle->split_mac; ++s) {
+		struct snapraid_split_handle* split = &handle->split_map[s];
+		int ret;
+
+		/* truncate any data that we know it's not valid */
+		ret = ftruncate(split->f, split->valid_size);
+		if (ret != 0) {
+			/* LCOV_EXCL_START */
+			log_fatal("Error truncating the parity file '%s' to size %" PRIu64 ". %s.\n", split->path, split->valid_size, strerror(errno));
+			f_ret = -1;
+			/* LCOV_EXCL_STOP */
+
+			/* continue to truncate the others */
+		}
+	}
+
+	return f_ret;
+}
+
 int parity_close(struct snapraid_parity_handle* handle)
 {
 	unsigned s;
@@ -826,6 +860,10 @@ int parity_write(struct snapraid_parity_handle* handle, block_off_t pos, unsigne
 		/* LCOV_EXCL_STOP */
 	}
 
+	/* update the valid range */
+	if (split->valid_size < offset + block_size)
+		split->valid_size = offset + block_size;
+
 	write_ret = pwrite(split->f, block_buffer, block_size, offset);
 	if (write_ret != (ssize_t)block_size) { /* conversion is safe because block_size is always small */
 		/* LCOV_EXCL_START */
@@ -867,6 +905,14 @@ int parity_read(struct snapraid_parity_handle* handle, block_off_t pos, unsigned
 		/* LCOV_EXCL_STOP */
 	}
 
+	/* if read is completely out of the valid range */
+	if (offset >= split->valid_size) {
+		/* LCOV_EXCL_START */
+		out("Missing data reading file '%s' at offset %" PRIu64 " for size %u.\n", split->path, offset, block_size);
+		return -1;
+		/* LCOV_EXCL_STOP */
+	}
+
 	count = 0;
 	do {
 		read_ret = pread(split->f, block_buffer + count, block_size - count, offset + count);
diff --git a/cmdline/parity.h b/cmdline/parity.h
index 056362e..3380eb7 100644
--- a/cmdline/parity.h
+++ b/cmdline/parity.h
@@ -36,6 +36,16 @@ struct snapraid_split_handle {
 	 */
 	data_off_t size;
 
+	/**
+	 * Valid size of the parity split.
+	 * This is the size effectively written, and not the result of a chsize operation.
+	 * It's used to make read operations failing if read over that size.
+	 *
+	 * Parity is also truncated to that size when fixing it, in case of a Break (Ctrl+C)
+	 * of the program.
+	 */
+	data_off_t valid_size;
+
 	/**
 	 * Artificial size limit for testing.
 	 * 0 means unlimited.
@@ -113,6 +123,11 @@ int parity_open(struct snapraid_parity_handle* handle, const struct snapraid_par
  */
 int parity_sync(struct snapraid_parity_handle* handle);
 
+/**
+ * Truncate the parity file to the valid size.
+ */
+int parity_truncate(struct snapraid_parity_handle* handle);
+
 /**
  * Close the parity file.
  */
diff --git a/cmdline/pool.c b/cmdline/pool.c
index 44e3510..85cfc40 100644
--- a/cmdline/pool.c
+++ b/cmdline/pool.c
@@ -369,7 +369,7 @@ static void make_link(tommy_hashdyn* poolset, const char* pool_dir, const char*
 #ifdef _WIN32
 		} else if (errno == EPERM) {
 			/* LCOV_EXCL_START */
-			log_fatal("You must run as Adminstrator to be able to create symlinks.\n");
+			log_fatal("You must run as Administrator to be able to create symlinks.\n");
 			exit(EXIT_FAILURE);
 			/* LCOV_EXCL_STOP */
 #endif
diff --git a/cmdline/portable.h b/cmdline/portable.h
index 053ad85..5c75428 100644
--- a/cmdline/portable.h
+++ b/cmdline/portable.h
@@ -35,7 +35,7 @@
 #define __USE_MINGW_ANSI_STDIO 1
 
 /**
- * Define the MSVCRT version targetting Windows Vista.
+ * Define the MSVCRT version targeting Windows Vista.
  */
 #define __MSVCRT_VERSION__ 0x0600
 
@@ -198,9 +198,11 @@
 #include <sys/types.h>
 #endif
 
-#if MAJOR_IN_MKDEV
+#if HAVE_SYS_MKDEV
 #include <sys/mkdev.h>
-#elif MAJOR_IN_SYSMACROS
+#endif
+
+#if HAVE_SYS_SYSMACROS_H
 #include <sys/sysmacros.h>
 #endif
 
@@ -387,14 +389,14 @@ void os_clear(void);
  *
  * If no log file is selected, it's 0.
  */
-FILE* stdlog;
+extern FILE* stdlog;
 
 /**
  * Exit codes for testing.
  */
-int exit_success;
-int exit_failure;
-int exit_sync_needed;
+extern int exit_success;
+extern int exit_failure;
+extern int exit_sync_needed;
 #undef EXIT_SUCCESS
 #undef EXIT_FAILURE
 #define EXIT_SUCCESS exit_success
diff --git a/cmdline/scan.c b/cmdline/scan.c
index 8e70ff3..f879cd3 100644
--- a/cmdline/scan.c
+++ b/cmdline/scan.c
@@ -501,7 +501,7 @@ static void scan_file_refresh(struct snapraid_scan* scan, const char* sub, struc
 			 * because the metadata in the directory is updated only when the file
 			 * is closed.
 			 *
-			 * The same happens for hardlinks that duplicate metatada.
+			 * The same happens for hardlinks that duplicate metadata.
 			 * The link metadata is updated only when the link is opened.
 			 * This extends also to st_size and st_nlink.
 			 *
diff --git a/cmdline/scrub.c b/cmdline/scrub.c
index 20a7ead..d69f3f0 100644
--- a/cmdline/scrub.c
+++ b/cmdline/scrub.c
@@ -665,7 +665,8 @@ static int state_scrub_process(struct snapraid_state* state, struct snapraid_par
 		log_fatal("DANGER! Unexpected data errors! The failing blocks are now marked as bad!\n");
 	if (io_error || silent_error) {
 		log_fatal("Use 'snapraid status' to list the bad blocks.\n");
-		log_fatal("Use 'snapraid -e fix' to recover.\n");
+		log_fatal("Use 'snapraid -e fix' to recover them.\n");
+		log_fatal("Use 'snapraid -p bad scrub' to recheck after fixing.\n");
 	}
 
 	log_tag("summary:error_file:%u\n", error);
diff --git a/cmdline/selftest.c b/cmdline/selftest.c
index b1e355a..8f79e5c 100644
--- a/cmdline/selftest.c
+++ b/cmdline/selftest.c
@@ -632,7 +632,7 @@ void selftest(void)
 	}
 	if (raid_test_par(RAID_MODE_CAUCHY, 1, 256) != 0) {
 		/* LCOV_EXCL_START */
-		log_fatal("Failed GEN Cauchy test sigle data disk\n");
+		log_fatal("Failed GEN Cauchy test single data disk\n");
 		exit(EXIT_FAILURE);
 		/* LCOV_EXCL_STOP */
 	}
diff --git a/cmdline/snapraid.c b/cmdline/snapraid.c
index 07103a6..ec4f839 100644
--- a/cmdline/snapraid.c
+++ b/cmdline/snapraid.c
@@ -1001,6 +1001,10 @@ int main(int argc, char* argv[])
 	switch (operation) {
 	case OPERATION_FIX :
 	case OPERATION_CHECK :
+	case OPERATION_SMART :
+	case OPERATION_DEVICES :
+	case OPERATION_SPINUP :
+	case OPERATION_SPINDOWN :
 		break;
 	default :
 		if (opt.force_device) {
diff --git a/cmdline/speed.c b/cmdline/speed.c
index f3ecdf8..73d2722 100644
--- a/cmdline/speed.c
+++ b/cmdline/speed.c
@@ -216,6 +216,7 @@ void speed(int period)
 	printf("%8s", "best");
 	printf("%8s", "murmur3");
 	printf("%8s", "spooky2");
+	printf("%8s", "metro");
 	printf("\n");
 
 	printf("%8s", "hash");
@@ -245,6 +246,14 @@ void speed(int period)
 			memhash(HASH_SPOOKY2, seed, digest, v[j], size);
 	} SPEED_STOP
 
+	printf("%8" PRIu64, ds / dt);
+	fflush(stdout);
+
+	SPEED_START {
+		for (j = 0; j < nd; ++j)
+			memhash(HASH_METRO, seed, digest, v[j], size);
+	} SPEED_STOP
+
 	printf("%8" PRIu64, ds / dt);
 	printf("\n");
 	printf("\n");
diff --git a/cmdline/state.c b/cmdline/state.c
index b09fba2..3b04e96 100644
--- a/cmdline/state.c
+++ b/cmdline/state.c
@@ -279,7 +279,7 @@ static void state_config_check(struct snapraid_state* state, const char* path, t
 				struct snapraid_disk* other = j->data;
 				if (disk->device == other->device) {
 					if (state->opt.force_device) {
-						/* note tha we just ignore the issue */
+						/* note that we just ignore the issue */
 						/* and we DON'T mark the disk to be skipped */
 						/* because we want to use these disks */
 						if (!state->opt.no_warnings)
@@ -310,15 +310,23 @@ static void state_config_check(struct snapraid_state* state, const char* path, t
 				for (l = 0; l < state->level; ++l) {
 					for (s = 0; s < state->parity[l].split_mac; ++s) {
 						if (disk->device == state->parity[l].split_map[s].device) {
-							/* LCOV_EXCL_START */
-							log_fatal("Disk '%s' and %s '%s' are on the same device.\n", disk->dir, lev_name(l), state->parity[l].split_map[s].path);
+							if (state->opt.force_device) {
+								/* note that we just ignore the issue */
+								/* and we DON'T mark the disk to be skipped */
+								/* because we want to use these disks */
+								if (!state->opt.no_warnings)
+									log_fatal("DANGER! Ignoring that disks '%s' and %s '%s' are on the same device\n", disk->dir, lev_name(l), state->parity[l].split_map[s].path);
+							} else {
+								/* LCOV_EXCL_START */
+								log_fatal("Disk '%s' and %s '%s' are on the same device.\n", disk->dir, lev_name(l), state->parity[l].split_map[s].path);
 #ifdef _WIN32
-							log_fatal("Both have the serial number '%" PRIx64 "'.\n", disk->device);
-							log_fatal("Try using the 'VolumeID' tool by 'Mark Russinovich'\n");
-							log_fatal("to change one of the disk serial.\n");
+								log_fatal("Both have the serial number '%" PRIx64 "'.\n", disk->device);
+								log_fatal("Try using the 'VolumeID' tool by 'Mark Russinovich'\n");
+								log_fatal("to change one of the disk serial.\n");
 #endif
-							exit(EXIT_FAILURE);
-							/* LCOV_EXCL_STOP */
+								exit(EXIT_FAILURE);
+								/* LCOV_EXCL_STOP */
+							}
 						}
 					}
 				}
@@ -364,7 +372,7 @@ static void state_config_check(struct snapraid_state* state, const char* path, t
 					for (t = 0; t < state->parity[j].split_mac; ++t) {
 						if (state->parity[l].split_map[s].device == state->parity[j].split_map[t].device) {
 							if (state->opt.force_device) {
-								/* note tha we just ignore the issue */
+								/* note that we just ignore the issue */
 								/* and we DON'T mark the disk to be skipped */
 								/* because we want to use these disks */
 								if (!state->opt.no_warnings)
@@ -623,7 +631,7 @@ void state_config(struct snapraid_state* state, const char* path, const char* co
 			}
 			state->block_size *= KIBI;
 		} else if (strcmp(tag, "hashsize") == 0
-			|| strcmp(tag, "hash_size") == 0 /* v11.0 used incorretly this one, kept now for backward compatibility */
+			|| strcmp(tag, "hash_size") == 0 /* v11.0 used incorrectly this one, kept now for backward compatibility */
 		) {
 			uint32_t hash_size;
 
@@ -1618,7 +1626,7 @@ static void state_content_check(struct snapraid_state* state, const char* path)
 /**
  * Check if the position is REQUIRED, or we can completely clear it from the state.
  *
- * Note that position with only DELETED blocks are discarged.
+ * Note that position with only DELETED blocks are discharged.
  */
 static int fs_position_is_required(struct snapraid_state* state, block_off_t pos)
 {
@@ -1844,7 +1852,7 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 			if (state->block_size == 0) {
 				/* LCOV_EXCL_START */
 				decoding_error(path, f);
-				log_fatal("Internal incosistency due zero blocksize!\n");
+				log_fatal("Internal inconsistency due zero blocksize!\n");
 				exit(EXIT_FAILURE);
 				/* LCOV_EXCL_STOP */
 			}
@@ -2398,6 +2406,9 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 			case 'k' :
 				state->hash = HASH_SPOOKY2;
 				break;
+			case 'm' :
+				state->hash = HASH_METRO;
+				break;
 			default :
 				/* LCOV_EXCL_START */
 				decoding_error(path, f);
@@ -2425,6 +2436,9 @@ static void state_read_content(struct snapraid_state* state, const char* path, S
 			case 'k' :
 				state->prevhash = HASH_SPOOKY2;
 				break;
+			case 'm' :
+				state->prevhash = HASH_METRO;
+				break;
 			default :
 				/* LCOV_EXCL_START */
 				decoding_error(path, f);
@@ -2947,6 +2961,8 @@ static void* state_write_thread(void* arg)
 		sputc('u', f);
 	} else if (state->hash == HASH_SPOOKY2) {
 		sputc('k', f);
+	} else if (state->hash == HASH_METRO) {
+		sputc('m', f);
 	} else {
 		/* LCOV_EXCL_START */
 		log_fatal("Unexpected hash when writing the content file '%s'.\n", serrorfile(f));
@@ -2970,6 +2986,8 @@ static void* state_write_thread(void* arg)
 				sputc('u', f);
 			} else if (state->prevhash == HASH_SPOOKY2) {
 				sputc('k', f);
+			} else if (state->prevhash == HASH_METRO) {
+				sputc('m', f);
 			} else {
 				/* LCOV_EXCL_START */
 				log_fatal("Unexpected prevhash when writing the content file '%s'.\n", serrorfile(f));
@@ -3837,10 +3855,14 @@ struct state_verify_thread_context {
 static void* state_verify_thread(void* arg)
 {
 	struct state_verify_thread_context* context = arg;
+	struct snapraid_content* content = context->content;
 	STREAM* f = context->f;
 	unsigned char buf[4];
 	uint32_t crc_stored;
 	uint32_t crc_computed;
+	uint64_t start;
+
+	start = tick_ms();
 
 	if (sdeplete(f, buf) != 0) {
 		/* LCOV_EXCL_START */
@@ -3872,6 +3894,8 @@ static void* state_verify_thread(void* arg)
 		/* LCOV_EXCL_STOP */
 	}
 
+	msg_progress("Verified %s in %" PRIu64 " seconds\n", content->content, (tick_ms() - start) / 1000);
+
 	return 0;
 }
 
@@ -4155,7 +4179,7 @@ void state_filter(struct snapraid_state* state, tommy_list* filterlist_file, tom
 		}
 	}
 
-	/* if we are filtering by disk, exclude any parity not explicitely included */
+	/* if we are filtering by disk, exclude any parity not explicitly included */
 	if (!tommy_list_empty(filterlist_disk)) {
 		/* for each parity disk */
 		for (l = 0; l < state->level; ++l) {
@@ -4463,7 +4487,8 @@ int state_progress(struct snapraid_state* state, struct snapraid_io* io, block_o
 	) {
 		time_t elapsed;
 		unsigned out_perc = 0;
-		unsigned out_speed = 0;
+		unsigned out_size_speed = 0;
+		unsigned out_block_speed = 0;
 		unsigned out_cpu = 0;
 		unsigned out_eta = 0;
 		int out_computed = 0;
@@ -4536,7 +4561,11 @@ int state_progress(struct snapraid_state* state, struct snapraid_io* io, block_o
 
 			/* estimate the speed in MB/s */
 			if (delta_time != 0)
-				out_speed = (unsigned)(delta_size / MEGA / delta_time);
+				out_size_speed = (unsigned)(delta_size / MEGA / delta_time);
+
+			/* estimate the speed in block/s */
+			if (delta_pos != 0)
+				out_block_speed = (unsigned)(delta_pos / delta_time);
 
 			/* estimate the cpu usage percentage */
 			if (delta_tick_total != 0)
@@ -4556,12 +4585,13 @@ int state_progress(struct snapraid_state* state, struct snapraid_io* io, block_o
 		}
 
 		if (state->opt.gui) {
-			log_tag("run:pos:%u:%u:%" PRIu64 ":%u:%u:%u:%u:%" PRIu64 "\n", blockpos, countpos, countsize, out_perc, out_eta, out_speed, out_cpu, (uint64_t)elapsed);
+			log_tag("run:pos:%u:%u:%" PRIu64 ":%u:%u:%u:%u:%" PRIu64 "\n", blockpos, countpos, countsize, out_perc, out_eta, out_size_speed, out_cpu, (uint64_t)elapsed);
 			log_flush();
 		} else {
 			msg_bar("%u%%, %u MB", out_perc, (unsigned)(countsize / MEGA));
 			if (out_computed) {
-				msg_bar(", %u MB/s", out_speed);
+				msg_bar(", %u MB/s", out_size_speed);
+				msg_bar(", %u block/s", out_block_speed);
 				msg_bar(", CPU %u%%", out_cpu);
 				msg_bar(", %u:%02u ETA", out_eta / 60, out_eta % 60);
 			}
diff --git a/cmdline/state.h b/cmdline/state.h
index cbc1a55..4794758 100644
--- a/cmdline/state.h
+++ b/cmdline/state.h
@@ -261,7 +261,7 @@ void state_rehash(struct snapraid_state* state);
  */
 #define SCRUB_AUTO -1 /**< Automatic selection. */
 #define SCRUB_BAD -2 /**< Scrub only the bad blocks. */
-#define SCRUB_NEW -3 /**< Scub the new blocks. */
+#define SCRUB_NEW -3 /**< Scrub the new blocks. */
 #define SCRUB_FULL -4 /**< Scrub everything. */
 #define SCRUB_EVEN -5 /**< Even blocks. */
 
diff --git a/cmdline/stream.c b/cmdline/stream.c
index b7bb2eb..f28338f 100644
--- a/cmdline/stream.c
+++ b/cmdline/stream.c
@@ -112,7 +112,7 @@ int sopen_multi_file(STREAM* s, unsigned i, const char* file)
 
 	pathcpy(s->handle[i].path, sizeof(s->handle[i].path), file);
 
-	/* O_EXCL to be resilent ensure to always create a new file and not use a stale link to the original file */
+	/* O_EXCL to be resilient ensure to always create a new file and not use a stale link to the original file */
 	f = open(file, O_WRONLY | O_CREAT | O_EXCL | O_BINARY | O_SEQUENTIAL, 0600);
 	if (f == -1) {
 		/* LCOV_EXCL_START */
@@ -363,7 +363,7 @@ int sgettok(STREAM* f, char* str, int size)
 			break;
 		}
 		if (c == '\n') {
-			/* remove ending carrige return to support the Windows CR+LF format */
+			/* remove ending carriage return to support the Windows CR+LF format */
 			if (i != str && i[-1] == '\r')
 				--i;
 			sungetc(c, f);
@@ -429,7 +429,7 @@ int sgetline(STREAM* f, char* str, int size)
 		while (1) {
 			c = *pos++;
 			if (c == '\n') {
-				/* remove ending carrige return to support the Windows CR+LF format */
+				/* remove ending carriage return to support the Windows CR+LF format */
 				if (i != str && i[-1] == '\r')
 					--i;
 				--pos;
@@ -455,7 +455,7 @@ int sgetline(STREAM* f, char* str, int size)
 				/* LCOV_EXCL_STOP */
 			}
 			if (c == '\n') {
-				/* remove ending carrige return to support the Windows CR+LF format */
+				/* remove ending carriage return to support the Windows CR+LF format */
 				if (i != str && i[-1] == '\r')
 					--i;
 				sungetc(c, f);
diff --git a/cmdline/stream.h b/cmdline/stream.h
index 35b941f..6ec3391 100644
--- a/cmdline/stream.h
+++ b/cmdline/stream.h
@@ -28,7 +28,7 @@
  *
  * It's not a constant for testing purpose.
  */
-unsigned STREAM_SIZE;
+extern unsigned STREAM_SIZE;
 
 #define STREAM_STATE_READ 0 /**< The stream is in a normal state of read. */
 #define STREAM_STATE_WRITE 1 /**< The stream is in a normal state of write. */
diff --git a/cmdline/support.c b/cmdline/support.c
index 80dfa5c..16d0229 100644
--- a/cmdline/support.c
+++ b/cmdline/support.c
@@ -79,6 +79,7 @@ void lock_done(void)
 /* print */
 
 int msg_level = 0;
+FILE* stdlog = 0;
 
 /*
  * Note that in the following functions we always flush both
@@ -811,7 +812,7 @@ int mkancestor(const char* file)
 	}
 
 #ifdef _WIN32
-	/* if it's a drive specificaion like "C:" */
+	/* if it's a drive specification like "C:" */
 	if (isalpha(dir[0]) && dir[1] == ':' && dir[2] == 0) {
 		/* nothing more to do */
 		return 0;
@@ -1236,7 +1237,7 @@ int advise_read(struct advise_struct* advise, int f, data_off_t offset, data_off
 	 * non-blocking and do this work in a workqueue (or via some kind of
 	 * callback/continuation scheme).  My worry is just doing this if a user
 	 * application does something crazy, like request gigabytes and gigabytes
-	 * of readahead, and then repents of their craziness, there should be a
+	 * of readahead, and then repented of their craziness, there should be a
 	 * way of cancelling the readahead request.  Today, the user can just
 	 * kill the application.  But if we simply shove the work to a kernel
 	 * thread, it becomes a lot harder to cancel the readahead request.  We'd
@@ -1632,16 +1633,16 @@ void thread_cond_wait(pthread_cond_t* cond, pthread_mutex_t* mutex)
 /**
  * Implementation note about conditional variables.
  *
- * The conditional variables can be signaled inside or ouside the mutex,
- * what is better it's debatable but in general doing that ouside the mutex,
+ * The conditional variables can be signaled inside or outside the mutex,
+ * what is better it's debatable but in general doing that outside the mutex,
  * reduces the number of context switches.
  *
- * But when when testing with helgrind and drd, this disallows such tools to
+ * But when testing with helgrind and drd, this disallows such tools to
  * to see the dependency between the signal and the wait.
  *
  * To avoid it we signal everything inside the mutex. And we do this in both
- * test mode (with CHERCKER defined) and release mode (CHECKER not defined),
- * to be on the safe side and avoid any difference in beaviour between test and
+ * test mode (with CHECKER defined) and release mode (CHECKER not defined),
+ * to be on the safe side and avoid any difference in behaviour between test and
  * release.
  *
  * Here some interesting discussion:
diff --git a/cmdline/support.h b/cmdline/support.h
index 3b75b38..e7e76b5 100644
--- a/cmdline/support.h
+++ b/cmdline/support.h
@@ -109,7 +109,7 @@ void log_flush(void);
 /**
  * Pointer to log function.
  */
-typedef void fptr(const char* format, ...);
+typedef void fptr(const char* format, ...) __attribute__((format(attribute_printf, 1, 2)));
 
 /****************************************************************************/
 /* message */
@@ -415,7 +415,7 @@ int smartctl_flush(FILE* f, const char* file, const char* name);
  *
  * Ensure to change that before starting any thread.
  */
-int thread_cond_signal_outside;
+extern int thread_cond_signal_outside;
 
 /**
  * Thread wrappers to handle error conditions.
diff --git a/cmdline/sync.c b/cmdline/sync.c
index 0d12590..96a23c8 100644
--- a/cmdline/sync.c
+++ b/cmdline/sync.c
@@ -1016,7 +1016,7 @@ static int state_sync_process(struct snapraid_state* state, struct snapraid_pari
 		}
 
 		/* if we have only silent errors we can try to fix them on-the-fly */
-		/* note the the fix is not written to disk, but used only to */
+		/* note the fix is not written to disk, but used only to */
 		/* compute the new parity */
 		if (!error_on_this_block && !io_error_on_this_block && silent_error_on_this_block) {
 			unsigned failed_mac;
@@ -1536,7 +1536,7 @@ int state_sync(struct snapraid_state* state, block_off_t blockstart, block_off_t
 				data_off_t out_size;
 				parity_size(&parity_handle[l], &out_size);
 				parity_overflow(state, out_size);
-				log_fatal("WARNING! Without an usable %s file, it isn't possible to sync.\n", lev_name(l));
+				log_fatal("WARNING! Without a usable %s file, it isn't possible to sync.\n", lev_name(l));
 				exit(EXIT_FAILURE);
 				/* LCOV_EXCL_STOP */
 			}
diff --git a/cmdline/unix.c b/cmdline/unix.c
index 351cfba..2b897fe 100644
--- a/cmdline/unix.c
+++ b/cmdline/unix.c
@@ -632,7 +632,7 @@ int filephy(const char* path, uint64_t size, uint64_t* physical)
 	/* In this way we keep them in the directory traversal order */
 	/* that at least keeps files in the same directory together. */
 	/* Note also that in newer file-system with snapshot, like ZFS, */
-	/* the inode doesn't represent evenmore the disk position, because files */
+	/* the inode doesn't represent even more the disk position, because files */
 	/* are not overwritten in place, but rewritten in another location */
 	/* of the disk. */
 	*physical = FILEPHY_UNREPORTED_OFFSET;
diff --git a/cmdline/unix.h b/cmdline/unix.h
index 8b190ce..62da33a 100644
--- a/cmdline/unix.h
+++ b/cmdline/unix.h
@@ -59,7 +59,7 @@ int dirent_hidden(struct dirent* dd);
 const char* stat_desc(struct stat* st);
 
 /**
- * Return the aligment requirement for direct IO.
+ * Return the alignment requirement for direct IO.
  */
 size_t direct_size(void);
 
diff --git a/cmdline/util.c b/cmdline/util.c
index 1a35b85..7de2bab 100644
--- a/cmdline/util.c
+++ b/cmdline/util.c
@@ -470,8 +470,24 @@ static inline uint64_t util_rotl64(uint64_t x, int8_t r)
 	return (x << r) | (x >> (64 - r));
 }
 
+/*
+ * Rotate right.
+ * In x86/x64 they are optimized with a single assembler instruction.
+ */
+#if 0 /* unused */
+static inline uint32_t util_rotr32(uint32_t x, int8_t r)
+{
+	return (x >> r) | (x << (32 - r));
+}
+#endif
+static inline uint64_t util_rotr64(uint64_t x, int8_t r)
+{
+	return (x >> r) | (x << (64 - r));
+}
+
+
 /**
- * Swap endianess.
+ * Swap endianness.
  * They are needed only if BigEndian.
  */
 #if defined(__GNUC__)
@@ -502,6 +518,18 @@ static inline uint64_t util_swap64(uint64_t v)
 }
 #endif
 
+static inline uint8_t util_read8(const void* void_ptr)
+{
+	const uint8_t* ptr = void_ptr;
+	return ptr[0];
+}
+
+static inline uint16_t util_read16(const void* void_ptr)
+{
+	const uint8_t* ptr = void_ptr;
+	return ptr[0] + (ptr[1] << 8);
+}
+
 static inline uint32_t util_read32(const void* ptr)
 {
 	uint32_t v;
@@ -543,6 +571,7 @@ static inline void util_write64(void* ptr, uint64_t v)
 
 #include "murmur3.c"
 #include "spooky2.c"
+#include "metro.c"
 
 void memhash(unsigned kind, const unsigned char* seed, void* digest, const void* src, size_t size)
 {
@@ -553,6 +582,9 @@ void memhash(unsigned kind, const unsigned char* seed, void* digest, const void*
 	case HASH_SPOOKY2 :
 		SpookyHash128(src, size, seed, digest);
 		break;
+	case HASH_METRO :
+		MetroHash128(src, size, seed, digest);
+		break;
 	default :
 		/* LCOV_EXCL_START */
 		log_fatal("Internal inconsistency in hash function %u\n", kind);
@@ -568,6 +600,7 @@ const char* hash_config_name(unsigned kind)
 	case HASH_UNDEFINED : return "undefined";
 	case HASH_MURMUR3 : return "murmur3";
 	case HASH_SPOOKY2 : return "spooky2";
+	case HASH_METRO : return "metro";
 	default :
 		/* LCOV_EXCL_START */
 		return "unknown";
diff --git a/cmdline/util.h b/cmdline/util.h
index 1661a9d..8717a14 100644
--- a/cmdline/util.h
+++ b/cmdline/util.h
@@ -161,7 +161,7 @@ static inline uint32_t crc32c_plain(uint32_t crc, const unsigned char* ptr, unsi
 /**
  * Compute the CRC-32 (Castagnoli)
  */
-uint32_t (*crc32c)(uint32_t crc, const unsigned char* ptr, unsigned size);
+extern uint32_t (*crc32c)(uint32_t crc, const unsigned char* ptr, unsigned size);
 
 /**
  * Internal entry points for testing.
@@ -188,6 +188,7 @@ void crc32c_init(void);
 #define HASH_UNDEFINED 0
 #define HASH_MURMUR3 1
 #define HASH_SPOOKY2 2
+#define HASH_METRO 3
 
 /**
  * Compute the HASH of a memory block.
diff --git a/config.h.in b/config.h.in
index 2c06e18..de1555e 100644
--- a/config.h.in
+++ b/config.h.in
@@ -224,6 +224,9 @@
 /* Define to 1 if you have the <sys/ioctl.h> header file. */
 #undef HAVE_SYS_IOCTL_H
 
+/* Define to 1 if you have the <sys/mkdev.h> header file. */
+#undef HAVE_SYS_MKDEV_H
+
 /* Define to 1 if you have the <sys/mount.h> header file. */
 #undef HAVE_SYS_MOUNT_H
 
@@ -240,6 +243,9 @@
 /* Define to 1 if you have the <sys/stat.h> header file. */
 #undef HAVE_SYS_STAT_H
 
+/* Define to 1 if you have the <sys/sysmacros.h> header file. */
+#undef HAVE_SYS_SYSMACROS_H
+
 /* Define to 1 if you have the <sys/types.h> header file. */
 #undef HAVE_SYS_TYPES_H
 
@@ -258,14 +264,6 @@
 /* Define to 1 if you have the `vsnprintf' function. */
 #undef HAVE_VSNPRINTF
 
-/* Define to 1 if `major', `minor', and `makedev' are declared in <mkdev.h>.
-   */
-#undef MAJOR_IN_MKDEV
-
-/* Define to 1 if `major', `minor', and `makedev' are declared in
-   <sysmacros.h>. */
-#undef MAJOR_IN_SYSMACROS
-
 /* Define to 1 if assertions should be disabled. */
 #undef NDEBUG
 
diff --git a/configure b/configure
index 62f8255..6580ed5 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.69 for snapraid 11.3.
+# Generated by GNU Autoconf 2.69 for snapraid 11.5.
 #
 #
 # Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
@@ -577,8 +577,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='snapraid'
 PACKAGE_TARNAME='snapraid'
-PACKAGE_VERSION='11.3'
-PACKAGE_STRING='snapraid 11.3'
+PACKAGE_VERSION='11.5'
+PACKAGE_STRING='snapraid 11.5'
 PACKAGE_BUGREPORT=''
 PACKAGE_URL='http://www.snapraid.it'
 
@@ -1304,7 +1304,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures snapraid 11.3 to adapt to many kinds of systems.
+\`configure' configures snapraid 11.5 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1374,7 +1374,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of snapraid 11.3:";;
+     short | recursive ) echo "Configuration of snapraid 11.5:";;
    esac
   cat <<\_ACEOF
 
@@ -1496,7 +1496,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-snapraid configure 11.3
+snapraid configure 11.5
 generated by GNU Autoconf 2.69
 
 Copyright (C) 2012 Free Software Foundation, Inc.
@@ -2102,7 +2102,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by snapraid $as_me 11.3, which was
+It was created by snapraid $as_me 11.5, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   $ $0 $@
@@ -2965,7 +2965,7 @@ fi
 
 # Define the identity of the package.
  PACKAGE='snapraid'
- VERSION='11.3'
+ VERSION='11.5'
 
 
 cat >>confdefs.h <<_ACEOF
@@ -4657,6 +4657,22 @@ $as_echo "no" >&6; }
 fi
 rm -f conftest*
 
+# This the new default for gcc 10
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CC-cc} accepts -fno-common" >&5
+$as_echo_n "checking whether ${CC-cc} accepts -fno-common... " >&6; }
+echo 'void f(){}' > conftest.c
+if test -z "`${CC-cc} -c -fno-common conftest.c 2>&1`"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+  CFLAGS="$CFLAGS -fno-common"
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+
+fi
+rm -f conftest*
+
 
 # Check whether --enable-largefile was given.
 if test "${enable_largefile+set}" = set; then :
@@ -5115,56 +5131,6 @@ $as_echo "#define HAVE_SYS_WAIT_H 1" >>confdefs.h
 
 fi
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether sys/types.h defines makedev" >&5
-$as_echo_n "checking whether sys/types.h defines makedev... " >&6; }
-if ${ac_cv_header_sys_types_h_makedev+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <sys/types.h>
-int
-main ()
-{
-return makedev(0, 0);
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_header_sys_types_h_makedev=yes
-else
-  ac_cv_header_sys_types_h_makedev=no
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_header_sys_types_h_makedev" >&5
-$as_echo "$ac_cv_header_sys_types_h_makedev" >&6; }
-
-if test $ac_cv_header_sys_types_h_makedev = no; then
-ac_fn_c_check_header_mongrel "$LINENO" "sys/mkdev.h" "ac_cv_header_sys_mkdev_h" "$ac_includes_default"
-if test "x$ac_cv_header_sys_mkdev_h" = xyes; then :
-
-$as_echo "#define MAJOR_IN_MKDEV 1" >>confdefs.h
-
-fi
-
-
-
-  if test $ac_cv_header_sys_mkdev_h = no; then
-    ac_fn_c_check_header_mongrel "$LINENO" "sys/sysmacros.h" "ac_cv_header_sys_sysmacros_h" "$ac_includes_default"
-if test "x$ac_cv_header_sys_sysmacros_h" = xyes; then :
-
-$as_echo "#define MAJOR_IN_SYSMACROS 1" >>confdefs.h
-
-fi
-
-
-  fi
-fi
-
 for ac_header in fcntl.h stddef.h stdint.h stdlib.h string.h limits.h
 do :
   as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
@@ -5204,7 +5170,7 @@ fi
 
 done
 
-for ac_header in sys/file.h sys/ioctl.h sys/vfs.h sys/statfs.h sys/param.h sys/mount.h
+for ac_header in sys/file.h sys/ioctl.h sys/vfs.h sys/statfs.h sys/param.h sys/mount.h sys/sysmacros.h sys/mkdev.h
 do :
   as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
 ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"
@@ -7373,7 +7339,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by snapraid $as_me 11.3, which was
+This file was extended by snapraid $as_me 11.5, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -7436,7 +7402,7 @@ _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
-snapraid config.status 11.3
+snapraid config.status 11.5
 configured by $0, generated by GNU Autoconf 2.69,
   with options \\"\$ac_cs_config\\"
 
diff --git a/configure.ac b/configure.ac
index 6486114..713a4cd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -17,11 +17,13 @@ AC_CHECK_PROG([SDE],[sde],[sde],[])
 AC_CHECK_PROG([ADVD2],[advd2],[advd2],[])
 AM_CONDITIONAL(HAVE_ADVD2, [test x"$ADVD2" != x])
 
-dnl Compiler option to improve stacktrace
+dnl Options to improve stacktrace
 AC_CHECK_CC_OPT([-fno-omit-frame-pointer], CFLAGS="$CFLAGS -fno-omit-frame-pointer", [])
 AC_CHECK_CC_OPT([-fno-inline-functions-called-once], CFLAGS="$CFLAGS -fno-inline-functions-called-once", [])
 AC_CHECK_CC_OPT([-fno-inline-small-functions], CFLAGS="$CFLAGS -fno-inline-small-functions", [])
 AC_CHECK_CC_OPT([-rdynamic], CFLAGS="$CFLAGS -rdynamic", [])
+# This the new default for gcc 10
+AC_CHECK_CC_OPT([-fno-common], CFLAGS="$CFLAGS -fno-common", [])
 
 dnl Checks for system.
 AC_SYS_LARGEFILE
@@ -31,11 +33,10 @@ AC_HEADER_ASSERT
 AC_HEADER_DIRENT
 AC_HEADER_TIME
 AC_HEADER_SYS_WAIT
-AC_HEADER_MAJOR
 AC_CHECK_HEADERS([fcntl.h stddef.h stdint.h stdlib.h string.h limits.h])
 AC_CHECK_HEADERS([unistd.h getopt.h fnmatch.h io.h inttypes.h byteswap.h])
 AC_CHECK_HEADERS([pthread.h math.h])
-AC_CHECK_HEADERS([sys/file.h sys/ioctl.h sys/vfs.h sys/statfs.h sys/param.h sys/mount.h])
+AC_CHECK_HEADERS([sys/file.h sys/ioctl.h sys/vfs.h sys/statfs.h sys/param.h sys/mount.h sys/sysmacros.h sys/mkdev.h])
 AC_CHECK_HEADERS([linux/fiemap.h linux/fs.h mach/mach_time.h execinfo.h])
 
 dnl Checks for typedefs, structures, and compiler characteristics.
diff --git a/raid/check.c b/raid/check.c
index 9bed933..d56a150 100644
--- a/raid/check.c
+++ b/raid/check.c
@@ -36,7 +36,7 @@
  * @ip[] Vector of @nv indexes of the valid parity blocks.
  *   The indexes start from 0. They must be in order.
  * @nd Number of data blocks.
- * @size Size of the blocks pointed by @v. It must be a multipler of 64.
+ * @size Size of the blocks pointed by @v. It must be a multiplier of 64.
  * @v Vector of pointers to the blocks of data and parity.
  *   It has (@nd + @ip[@nv - 1] + 1) elements. The starting elements are the
  *   blocks for data, following with the parity blocks.
diff --git a/raid/helper.h b/raid/helper.h
index bf68288..a663efd 100644
--- a/raid/helper.h
+++ b/raid/helper.h
@@ -23,7 +23,7 @@
  *
  * @n Number of integers currently in the vector.
  * @v Vector of integers already sorted.
- *   It must have extra space for the new elemet at the end.
+ *   It must have extra space for the new element at the end.
  * @i Value to insert.
  */
 void raid_insert(int n, int *v, int i);
diff --git a/raid/internal.h b/raid/internal.h
index 4465cb9..f8d3c78 100644
--- a/raid/internal.h
+++ b/raid/internal.h
@@ -174,7 +174,7 @@ void raid_recX_avx2(int nr, int *id, int *ip, int nd, size_t size, void **vv);
 /*
  * Internal naming.
  *
- * These are intented to provide access for testing.
+ * These are intended to provide access for testing.
  */
 const char *raid_gen1_tag(void);
 const char *raid_gen2_tag(void);
@@ -263,7 +263,7 @@ static __always_inline void raid_avx_end(void)
 	raid_sse_end();
 
 	/* reset the upper part of the ymm registers */
-	/* to avoid the 70 clocks penality on the next */
+	/* to avoid the 70 clocks penalty on the next */
 	/* xmm register use */
 	asm volatile ("vzeroupper" : : : "memory");
 }
diff --git a/raid/memory.h b/raid/memory.h
index de00614..53a428a 100644
--- a/raid/memory.h
+++ b/raid/memory.h
@@ -45,7 +45,7 @@
  *    gen2    6814 [MB/s]
  *    genz    3033 [MB/s]
  *
- * These are the results with displacement resulting in improvments
+ * These are the results with displacement resulting in improvements
  * in the order of 20% or more:
  *
  *            sse2
diff --git a/raid/raid.c b/raid/raid.c
index 3052675..ebdfd17 100644
--- a/raid/raid.c
+++ b/raid/raid.c
@@ -63,11 +63,11 @@
  * computation of triple parity using power coefficients.
  *
  * Another important property of the Cauchy matrix is that we can setup
- * the first two rows with coeffients equal at the RAID5 and RAID6 approach
- * decribed, resulting in a compatible extension, and requiring SSSE3
+ * the first two rows with coefficients equal at the RAID5 and RAID6 approach
+ * described, resulting in a compatible extension, and requiring SSSE3
  * or AVX2 instructions only if triple parity or beyond is used.
  *
- * The matrix is also adjusted, multipling each row by a constant factor
+ * The matrix is also adjusted, multiplying each row by a constant factor
  * to make the first column of all 1, to optimize the computation for
  * the first disk.
  *
@@ -147,7 +147,7 @@
  * "raid/test/speedtest.c" program.
  *
  * For comparison, the triple parity computation using the power
- * coeffients "1,2,2^-1" is only a little faster than the one based on
+ * coefficients "1,2,2^-1" is only a little faster than the one based on
  * the Cauchy matrix if SSSE3 or AVX2 is present.
  *
  *             int8   int32   int64    sse2   ssse3    avx2
@@ -205,12 +205,12 @@ void raid_zero(void *zero)
  * All these functions give the guarantee that parities are written
  * in order. First parity P, then parity Q, and so on.
  * This allows to specify the same memory buffer for multiple parities
- * knowning that you'll get the latest written one.
+ * knowing that you'll get the latest written one.
  * This characteristic is used by the raid_delta_gen() function to
  * avoid to damage unused parities in recovering.
  *
  * @nd Number of data blocks
- * @size Size of the blocks pointed by @v. It must be a multipler of 64.
+ * @size Size of the blocks pointed by @v. It must be a multiplier of 64.
  * @v Vector of pointers to the blocks of data and parity.
  *   It has (@nd + #parities) elements. The starting elements are the blocks
  *   for data, following with the parity blocks.
@@ -335,7 +335,7 @@ void raid_delta_gen(int nr, int *id, int *ip, int nd, size_t size, void **v)
 		} else {
 			/*
 			 * Unused parities are going to be rewritten with
-			 * not significative data, becase we don't have
+			 * not significative data, because we don't have
 			 * functions able to compute only a subset of
 			 * parities.
 			 *
@@ -483,7 +483,7 @@ void raid_rec2of2_int8(int *id, int *ip, int nd, size_t size, void **vv)
  *   The indexes start from 0. They must be in order.
  * @nd Number of data blocks.
  * @np Number of parity blocks.
- * @size Size of the blocks pointed by @v. It must be a multipler of 64.
+ * @size Size of the blocks pointed by @v. It must be a multiplier of 64.
  * @v Vector of pointers to the blocks of data and parity.
  *   It has (@nd + @np) elements. The starting elements are the blocks
  *   for data, following with the parity blocks.
diff --git a/raid/tables.c b/raid/tables.c
index 4903502..7828956 100644
--- a/raid/tables.c
+++ b/raid/tables.c
@@ -13662,8 +13662,8 @@ const uint8_t __aligned(256) raid_gfcauchypshufb[251][4][2][16] =
 /**
  * PSHUFB tables for generic multiplication.
  *
- * Indexes are [MULTIPLER][LH].
- * Where MULTIPLER is from 0 to 255, LH from 0 to 1.
+ * Indexes are [MULTIPLIER][LH].
+ * Where MULTIPLIER is from 0 to 255, LH from 0 to 1.
  */
 const uint8_t __aligned(256) raid_gfmulpshufb[256][2][16] =
 {
diff --git a/raid/test/Makefile b/raid/test/Makefile
index 229d5ad..6423fd1 100644
--- a/raid/test/Makefile
+++ b/raid/test/Makefile
@@ -3,7 +3,7 @@
 #
 # selftest - Runs the same selftest and speedtest executed at the module startup.
 # fulltest - Runs a more extensive test that checks all the built-in functions.
-# speetest - Runs a more complete speed test.
+# speedtest - Runs a more complete speed test.
 # invtest - Runs an extensive matrix inversion test of all the 377.342.351.231
 #           possible square submatrices of the Cauchy matrix used.
 # covtest - Runs a coverage test.
diff --git a/snapraid.1 b/snapraid.1
index 0fb9b7b..ce7aa9b 100644
--- a/snapraid.1
+++ b/snapraid.1
@@ -79,6 +79,9 @@ Beside the ability to recover from disk failures, other
 features of SnapRAID are:
 .PD 0
 .IP \(bu
+You can use disk already filled with files, without the need to
+reformat them. You will access them like now.
+.IP \(bu
 All your data is hashed to ensure data integrity and to avoid
 silent corruption.
 .IP \(bu
@@ -89,8 +92,6 @@ All the data in the other disks is safe.
 If you accidentally delete some files in a disk, you can
 recover them.
 .IP \(bu
-You can start with already filled disks.
-.IP \(bu
 The disks can have different sizes.
 .IP \(bu
 You can add disks at any time.
@@ -98,7 +99,7 @@ You can add disks at any time.
 It doesn\'t lock\-in your data. You can stop using SnapRAID at any
 time without the need to reformat or move data.
 .IP \(bu
-To access a file, a single disk needs to spin, saving power and
+To access a file, only a single disk needs to spin, saving power and
 producing less noise.
 .PD
 .PP
@@ -686,7 +687,7 @@ run \[dq]sync\[dq]. Later modifications are not taken into account.
 If bad blocks were detected, their block numbers are listed.
 To fix them, you can use the \[dq]fix \-e\[dq] command.
 .PP
-It also shows a graph representing the the last time each block
+It also shows a graph representing the last time each block
 was scrubbed or synced. Scrubbed blocks are shown with \'*\',
 blocks synced but not yet scrubbed with \'o\'.
 .PP
@@ -889,7 +890,7 @@ Use the filter options to select a subset of files or disks to operate on.
 To only fix the blocks marked bad during \[dq]sync\[dq] and \[dq]scrub\[dq],
 use the \-e, \-\-filter\-error option.
 As difference from other filter options, with this one the fixes are
-applied only to files that are not modified from the the latest \[dq]sync\[dq].
+applied only to files that are not modified from the latest \[dq]sync\[dq].
 .PP
 All the files that cannot be fixed are renamed adding the
 \[dq].unrecoverable\[dq] extension.
diff --git a/snapraid.d b/snapraid.d
index 82ccdb5..0cc6650 100644
--- a/snapraid.d
+++ b/snapraid.d
@@ -31,6 +31,8 @@ Description
 	Beside the ability to recover from disk failures, other
 	features of SnapRAID are:
 
+	* You can use disk already filled with files, without the need to
+		reformat them. You will access them like now.
 	* All your data is hashed to ensure data integrity and to avoid
 		silent corruption.
 	* If the failed disks are too many to allow a recovery,
@@ -38,12 +40,11 @@ Description
 		All the data in the other disks is safe.
 	* If you accidentally delete some files in a disk, you can
 		recover them.
-	* You can start with already filled disks.
 	* The disks can have different sizes.
 	* You can add disks at any time.
 	* It doesn't lock-in your data. You can stop using SnapRAID at any
 		time without the need to reformat or move data.
-	* To access a file, a single disk needs to spin, saving power and
+	* To access a file, only a single disk needs to spin, saving power and
 		producing less noise.
 
 	The official site of SnapRAID is:
@@ -400,7 +401,7 @@ Commands
 	If bad blocks were detected, their block numbers are listed.
 	To fix them, you can use the "fix -e" command.
 
-	It also shows a graph representing the the last time each block
+	It also shows a graph representing the last time each block
 	was scrubbed or synced. Scrubbed blocks are shown with '*',
 	blocks synced but not yet scrubbed with 'o'.
 
@@ -577,7 +578,7 @@ Commands
 	To only fix the blocks marked bad during "sync" and "scrub",
 	use the -e, --filter-error option.
 	As difference from other filter options, with this one the fixes are
-	applied only to files that are not modified from the the latest "sync".
+	applied only to files that are not modified from the latest "sync".
 
 	All the files that cannot be fixed are renamed adding the
 	".unrecoverable" extension.
diff --git a/snapraid.txt b/snapraid.txt
index 9621e04..78cfb35 100644
--- a/snapraid.txt
+++ b/snapraid.txt
@@ -38,6 +38,8 @@ big files that rarely change.
 Beside the ability to recover from disk failures, other
 features of SnapRAID are:
 
+* You can use disk already filled with files, without the need to
+  reformat them. You will access them like now.
 * All your data is hashed to ensure data integrity and to avoid
   silent corruption.
 * If the failed disks are too many to allow a recovery,
@@ -45,12 +47,11 @@ features of SnapRAID are:
   All the data in the other disks is safe.
 * If you accidentally delete some files in a disk, you can
   recover them.
-* You can start with already filled disks.
 * The disks can have different sizes.
 * You can add disks at any time.
 * It doesn't lock-in your data. You can stop using SnapRAID at any
   time without the need to reformat or move data.
-* To access a file, a single disk needs to spin, saving power and
+* To access a file, only a single disk needs to spin, saving power and
   producing less noise.
 
 The official site of SnapRAID is:
@@ -426,7 +427,7 @@ run "sync". Later modifications are not taken into account.
 If bad blocks were detected, their block numbers are listed.
 To fix them, you can use the "fix -e" command.
 
-It also shows a graph representing the the last time each block
+It also shows a graph representing the last time each block
 was scrubbed or synced. Scrubbed blocks are shown with '*',
 blocks synced but not yet scrubbed with 'o'.
 
@@ -617,7 +618,7 @@ Use the filter options to select a subset of files or disks to operate on.
 To only fix the blocks marked bad during "sync" and "scrub",
 use the -e, --filter-error option.
 As difference from other filter options, with this one the fixes are
-applied only to files that are not modified from the the latest "sync".
+applied only to files that are not modified from the latest "sync".
 
 All the files that cannot be fixed are renamed adding the
 ".unrecoverable" extension.
diff --git a/tommyds/tommychain.h b/tommyds/tommychain.h
index 12d2514..4ff3f1a 100644
--- a/tommyds/tommychain.h
+++ b/tommyds/tommychain.h
@@ -114,7 +114,7 @@ tommy_inline void tommy_chain_merge(tommy_chain* first, tommy_chain* second, tom
 
 /**
  * Merges two chains managing special degenerated cases.
- * It's funtionally equivalent at tommy_chain_merge() but faster with already ordered chains.
+ * It's functionally equivalent at tommy_chain_merge() but faster with already ordered chains.
  */
 tommy_inline void tommy_chain_merge_degenerated(tommy_chain* first, tommy_chain* second, tommy_compare_func* cmp)
 {
@@ -153,7 +153,7 @@ tommy_inline void tommy_chain_mergesort(tommy_chain* chain, tommy_compare_func*
 	/*
 	 * Bit buckets of chains.
 	 * Each bucket contains 2^i nodes or it's empty.
-	 * The chain at address TOMMY_BIT_MAX is an independet variable operating as "carry".
+	 * The chain at address TOMMY_BIT_MAX is an independent variable operating as "carry".
 	 * We keep it in the same "bit" vector to avoid reports from the valgrind tool sgcheck.
 	 */
 	tommy_chain bit[TOMMY_SIZE_BIT + 1];
diff --git a/tommyds/tommyhash.c b/tommyds/tommyhash.c
index cc7495d..71c4ef3 100644
--- a/tommyds/tommyhash.c
+++ b/tommyds/tommyhash.c
@@ -231,7 +231,7 @@ tommy_uint32_t tommy_strhash_u32(tommy_uint64_t init_val, const void* void_key)
 		key += 12;
 	}
 
-	/* for lengths that are multiplers of 12 we already have called mix */
+	/* for lengths that are multipliers of 12 we already have called mix */
 	/* this is different than the original lookup3 and the result won't match */
 
 	tommy_final(a, b, c);
diff --git a/tommyds/tommyhash.h b/tommyds/tommyhash.h
index 50d595c..e9bdba0 100644
--- a/tommyds/tommyhash.h
+++ b/tommyds/tommyhash.h
@@ -52,7 +52,7 @@
  * \param void_key Pointer to the data to hash.
  * \param key_len Size of the data to hash.
  * \note
- * This function is endianess independent.
+ * This function is endianness independent.
  * \return The hash value of 32 bits.
  */
 tommy_uint32_t tommy_hash_u32(tommy_uint32_t init_val, const void* void_key, tommy_size_t key_len);
@@ -72,14 +72,14 @@ tommy_uint32_t tommy_hash_u32(tommy_uint32_t init_val, const void* void_key, tom
  * \param void_key Pointer to the data to hash.
  * \param key_len Size of the data to hash.
  * \note
- * This function is endianess independent.
+ * This function is endianness independent.
  * \return The hash value of 64 bits.
  */
 tommy_uint64_t tommy_hash_u64(tommy_uint64_t init_val, const void* void_key, tommy_size_t key_len);
 
 /**
  * String hash function with a 32 bits result.
- * Implementation is based on the the Robert Jenkins "lookup3" hash 32 bits version,
+ * Implementation is based on Robert Jenkins "lookup3" hash 32 bits version,
  * from http://www.burtleburtle.net/bob/hash/doobs.html, function hashlittle().
  *
  * This hash is designed to handle strings with an unknown length. If you
@@ -90,7 +90,7 @@ tommy_uint64_t tommy_hash_u64(tommy_uint64_t init_val, const void* void_key, tom
  * Use 0 if not relevant.
  * \param void_key Pointer to the string to hash. It has to be 0 terminated.
  * \note
- * This function is endianess independent.
+ * This function is endianness independent.
  * \return The hash value of 32 bits.
  */
 tommy_uint32_t tommy_strhash_u32(tommy_uint64_t init_val, const void* void_key);
diff --git a/tommyds/tommyhashdyn.h b/tommyds/tommyhashdyn.h
index 73baba9..0ea042f 100644
--- a/tommyds/tommyhashdyn.h
+++ b/tommyds/tommyhashdyn.h
@@ -92,7 +92,7 @@
  *
  * To iterate over all the elements in the hashtable with the same key, you have to
  * use tommy_hashdyn_bucket() and follow the tommy_node::next pointer until NULL.
- * You have also to check explicitely for the key, as the bucket may contains
+ * You have also to check explicitly for the key, as the bucket may contains
  * different keys.
  *
  * \code
diff --git a/tommyds/tommylist.h b/tommyds/tommylist.h
index 42ef3ad..f70ad45 100644
--- a/tommyds/tommylist.h
+++ b/tommyds/tommylist.h
@@ -28,7 +28,7 @@
 /** \file
  * Double linked list for collisions into hashtables.
  *
- * This list is a double linked list mainly targetted for handling collisions
+ * This list is a double linked list mainly targeted for handling collisions
  * into an hashtables, but useable also as a generic list.
  *
  * The main feature of this list is to require only one pointer to represent the
@@ -294,7 +294,7 @@ tommy_inline void tommy_list_concat(tommy_list* first, tommy_list* second)
  * It's a stable merge sort with O(N*log(N)) worst complexity.
  * It's faster on degenerated cases like partially ordered lists.
  * \param cmp Compare function called with two elements.
- * The function should return <0 if the first element is less than the second, ==0 if equal, and >0 if greather.
+ * The function should return <0 if the first element is less than the second, ==0 if equal, and >0 if greater.
  */
 void tommy_list_sort(tommy_list* list, tommy_compare_func* cmp);
 
diff --git a/tommyds/tommytree.h b/tommyds/tommytree.h
index ada12c0..e56f865 100644
--- a/tommyds/tommytree.h
+++ b/tommyds/tommytree.h
@@ -33,7 +33,7 @@
  *
  * As difference than other tommy containers, duplicate elements cannot be inserted.
  *
- * To initialize a tree you have to call tommy_tree_init() specifing a comparison
+ * To initialize a tree you have to call tommy_tree_init() specifying a comparison
  * function that will define the order in the tree.
  *
  * \code
@@ -123,7 +123,7 @@ typedef struct tommy_tree_struct {
 
 /**
  * Initializes the tree.
- * \param cmp The comparison function that defines the orderin the tree.
+ * \param cmp The comparison function that defines the order in the tree.
  */
 void tommy_tree_init(tommy_tree* tree, tommy_compare_func* cmp);
 
diff --git a/tommyds/tommytypes.h b/tommyds/tommytypes.h
index 0608b15..8dc206b 100644
--- a/tommyds/tommytypes.h
+++ b/tommyds/tommytypes.h
@@ -227,7 +227,7 @@ typedef struct tommy_node_struct {
  * Compare function for elements.
  * \param obj_a Pointer to the first object to compare.
  * \param obj_b Pointer to the second object to compare.
- * \return <0 if the first element is less than the second, ==0 equal, >0 if greather.
+ * \return <0 if the first element is less than the second, ==0 equal, >0 if greater.
  *
  * This function is like the C strcmp().
  *