# hd-idle Reimplementation of _Christian Mueller's_ [hd-idle](http://hd-idle.sf.net) with some extra features. `hd-idle` is a utility program for spinning-down external disks after a period of idle time. Since most external IDE disk enclosures don't support setting the IDE idle timer, a program like `hd-idle` is required to spin down idle disks automatically. **Index** * [Extra features](#extra-features) * [Support ATA commands](#support-ata-commands) * [Monitor the skew between monitoring cycles](#monitor-the-skew-between-monitoring-cycles) * [Resolve symlinks in runtime](#resolve-symlinks-in-runtime) * [Log disk spin up](#log-disk-spin-up) * [Use disk partitions or device mapper to calculate activity](#use-disk-partitions-or-device-mapper-to-calculate-activity) * [Install](#Install) * [Precompiled binaries](#precompiled-binaries) * [Build from source](#build-from-source) * [Run hd-idle](#run-hd-idle) * [Configuration](#Configuration) * [Understand the logs](#understand-the-logs) * [Standard log](#standard-log) * [Log file](#log-file) * [Warning on spinning down disks](#warning-on-spinning-down-disks) * [Troubleshot](#Troubleshot) * [LUKS support](#luks-support) * [SCSI response not ok](#scsi-response-not-ok) ## Extra features List of extra features compared to the original `hd-idle`: ### Support ATA commands The implementation of `hd-idle` written by _Christian Mueller_ relies on the `SCSI` api to work. When listing the drives by id, disks starting with `usb` stop using the original implementation, but disk starting with `ata` do not. $ ls /dev/disk/by-id/ ata-WDC_WD40EZRX- ata-WDC_WD50EZRX- usb-WD_My_Book_1140_ [hdparm](https://en.wikipedia.org/wiki/Hdparm) on the other hand always stops the drives without any problems. It uses `ATA` api calls to send disks to standby. `hd-idle` comes with `ATA` commands support to replicate `hdparm`'s api calls. ### Monitor the skew between monitoring cycles Identify if the sleep took longer than expected and reset the spun down flag if it waited too long for the main loop sleep. This should capture suspend events as well as excessive machine load. ### Resolve symlinks in runtime `hd-idle` can resolve disk symlinks also in runtime. Disks added after application's start won't be hidden. ### Log disk spin up Show in standard output when disks spin up. ### Use disk partitions or device mapper to calculate activity The disk activity is calculated by watching read/write changes on partition or device mapper level instead of disk level. This is required for kernels newer than 5.4 LTS, because disk monitoring tools change read/write values on disk level, although there's no real activity on the disk itself. When using LUKS, activity will happen on the device mapper device mapped to the corresponding disk. ## Install There are various ways of installing `hd-idle`: ### Precompiled binaries Precompiled binaries for released versions are available in the [*releases*](https://github.com/adelolmo/hd-idle/releases) section. ### Build from source To build `hd-idle` from the source code yourself you need to have a working Go environment with [version 1.16 or greater installed](http://golang.org/doc/install). Open a terminal and execute these commands: git clone https://github.com/adelolmo/hd-idle cd hd-idle make On Debian you can also build the package yourself using `dpkg-buildpackage`: git clone https://github.com/adelolmo/hd-idle.git cd hd-idle dpkg-buildpackage -a armhf -us -uc -b In the example above, the package is built for `armhf`, but you can build it also for the platforms `i386`, `amd64`, and `arm64` by substituting the parameter `-a`. Then install the package: # dpkg -i ../hd-idle*.deb ## Run hd-idle In order to run `hd-idle`, type: $ hd-idle This will start `hd-idle` with the default options, causing all `SCSI` (read: USB, Firewire, SCSI, ...) hard disks to spin down after 10 minutes of inactivity. If the Debian package was installed, after editing `/etc/default/hd-idle` and enabling it (`START_HD_IDLE=true`), run hd-idle with: # systemctl start hd-idle To enable `hd-idle` on reboot: # systemctl enable hd-idle Please note that `hd-idle` uses */proc/diskstats* to read disk statistics. If this file is not present, `hd-idle` won't work. In case of problems, use the debug option *-d* to get further information. ## Configuration Command line options: + -a *name* Set device name of disks for subsequent idle-time parameters *-i*. This parameter is optional in the sense that there's a default entry for all disks which are not named otherwise by using this parameter. This can also be a symlink (e.g. /dev/disk/by-uuid/...) + -i *idle_time* Idle time in seconds for the currently named disk(s) (-a *name*) or for all disks. Setting this value to `0` will never spin down the disk(s). + -c *command_type* Api call to stop the device. Possible values are `scsi` (default value) and `ata`. + -p *power_condition* Power condition to send with the issued SCSI START STOP UNIT command. Possible values are `0-15` (inclusive). The default value of `0` works fine for disks accessible via the SCSI layer (USB, IEEE1394, ...), but it will *NOT* work as intended with real SCSI / SAS disks. A stopped SAS disk will not start up automatically on access, but requires a startup command for reactivation. Useful values for SAS disks are `2` for idle and `3` for standby. + -s *symlink_policy* Set the policy to resolve symlinks for devices. If set to `0`, symlinks are resolved only on start. If set to `1`, symlinks are also resolved on runtime until success. By default symlinks are only resolved on start. If the symlink doesn't resolve to a device, the default configuration will be applied. + -l *logfile* Name of logfile (written only after a disk has spun up or down). Please note that this option might cause the disk which holds the logfile to spin up just because another disk had some activity. On single-disk systems, this option should not cause any additional spinups. On systems with more than one disk, the disk where the log is written will be spun up. On raspberry based systems the log should be written to the SD card. Miscellaneous options: + -t *disk* Spin-down the specified disk immediately and exit. + -d Debug mode. It will print debugging info to stdout/stderr (/var/log/syslog if started with systemctl) + -h Print usage information. Regarding the parameter *-a*: The parameter *-a* can be used to set a filter on the disk's device name (omit /dev/) for subsequent idle-time settings. 1) A *-i* option before the first *-a* option will set the default idle time. 2) In order to disable spin-down of disks per default, and then re-enable spin-down on selected disks, set the default idle time to 0. Example: ``` hd-idle -i 0 -a sda -i 300 -a sdb -i 1200 ``` This example sets the default idle time to 0 (meaning hd-idle will never try to spin down a disk) and the default api command to `scsi`, then sets explicit idle times for disks which have the string `sda` or `sdb` in their device name. 3) The option *-c* allows to set the api call that sends the spindown command. Possible values are `scsi` (the default value) or `ata`. Example: ``` hd-idle -i 0 -c ata -a sda -i 300 -a sdb -i 1200 -c scsi ``` This example sets the default idle time to 0 (meaning hd-idle will never try to spin down a disk) and the default api command to `ata`, then sets explicit idle times for disks which have the string `sda` or `sdb` in their device name and sets `sdb` to use `scsi` api command. ## Understand the logs By default `hd-idle` only logs to the standard output. You can find them in the syslog if the application starts via service. If you set the log file (`-l` flag) then the application writes extra details to it. (Check the [Configuration](#Configuration) section). ### Standard log The standard log output registers two kinds of events: * disk spin up * disk spin down ``` Aug 8 00:14:55 enterprise hd-idle[9958]: sda spindown Aug 8 00:14:55 enterprise hd-idle[9958]: sdb spindown Aug 8 00:14:56 enterprise hd-idle[9958]: sdc spindown Aug 8 00:17:55 enterprise hd-idle[9958]: sdb spinup Aug 8 00:28:55 enterprise hd-idle[9958]: sdb spindown ``` ### Log file You can enable the log file with the flag `-l` followed by the log path. (Check the [Configuration](#Configuration) section). This is the kind of entry shown in the log file: ``` date: 2020-07-30, time: 05:28:01, disk: sdc, running: 601, stopped: 76654 ``` Explanation: * `date` and `time` when the disk spins up. * `disk` involved. * `running` seconds the device was running before it spun down the last time. * `stopped` seconds since last spin down. This is the time the disk was asleep before spinning up. **Important Note:** The log file is written after a full cycle of running-stopped-wakeup. A bit more on `running` explained with the above example: | timestamp |disk spin| event |new disk spin| running | stopped | |:-----------------:|:-------:|:-----------:|:-----------:|:------------------------:|:-------------------------------------------------------:| |2020-07-29 07:59:57| down |disk activity| up | ? | ? | |2020-07-29 08:09:58| up | go to sleep | down | - | - | |2020-07-30 05:28:01| down |disk activity| up |08:09:58 - 07:59:57 = 601s|2020-07-30 05:28:01 - 2020-07-29 08:09:58 = ~21h (76654s)| Explanation: At 07:59:57 the disk is on standby and hd-idle detects disk activity. At 08:09:58 the disk is active and hd-idle determines inactivity of the disk and spins it down. At 05:28:01 on the next day the disk is on standby and hd-idle detects disk activity. It writes on the log file 601s of previous disk spin up and ~21h of standby. ## Warning on spinning down disks A word of caution: hard disks don't like spinning up too often. Laptop disks are more robust in this respect than desktop disks but if you set your disks to spin down after a few seconds you may damage the disk over time due to the stress the spin-up causes on the spindle motor and bearings. It seems that manufacturers recommend a minimum idle time of 3-5 minutes, the default in `hd-idle` is 10 minutes. You have been warned... # Troubleshot This section covers some usual issues that user's face while using `hd-idle`. ## LUKS support Using encrypted disk or partitions with LUKS is supported by the use of symlinks. 1. Run the following command with you're disk mounted: `sudo lsblk /dev/sd* -o PATH,FSSIZE,LABEL,UUID,PARTLABEL,PARTUUID,MODEL,SIZE,SERIAL,TYPE,WWN` ``` PATH FSSIZE LABEL UUID PARTLABEL PARTUUID MODEL SIZE SERIAL TYPE WWN /dev/sde ST400 3.7T ZGY0LB disk 0x5000c500a3d1d419 /dev/sde1 100e952e-0ffb-4b73-bb1a-8401d4fe56c0 dropbox 14a81aa8-c2c9-448e-967b-85d87dc9b488 1T part 0x5000c500a3d1d419 /dev/sde1 100e952e-0ffb-4b73-bb1a-8401d4fe56c0 dropbox 14a81aa8-c2c9-448e-967b-85d87dc9b488 1T part 0x5000c500a3d1d419 /dev/sde2 2.6T three 175e2227-d24f-4ad0-9e42-2ddb8846682d d2792423-3c07-44fe-ab6b-a1aca61c73a5 2.7T part 0x5000c500a3d1d419 /dev/sde2 2.6T three 175e2227-d24f-4ad0-9e42-2ddb8846682d d2792423-3c07-44fe-ab6b-a1aca61c73a5 2.7T part 0x5000c500a3d1d419 /dev/mapper/luks-100e952e-0ffb-4b73-bb1a-8401d4fe56c0 1007.8G dropbox 649dd15e-6750-472c-8185-4d76bffc2490 1024G crypt ``` You have to take symlinks that resolve to disk devices: `/dev/sd*`. In the example above `/dev/mapper/luks-100e952e-0ffb-4b73-bb1a-8401d4fe56c0` is the Path to the encrypted partition, which WWN is `0x5000c500a3d1d419`. 2. Run the following command to see which devices the system has identified using `by-id`: `sudo ls -lv /dev/disk/by-id/` Output: ``` lrwxrwxrwx 1 root root 9 Jul 18 15:56 ata-ST4000DM005-2DP166_ZGY0LBRB -> ../../sde lrwxrwxrwx 1 root root 10 Jul 18 16:01 ata-ST4000DM005-2DP166_ZGY0LBRB-part1 -> ../../sde1 lrwxrwxrwx 1 root root 10 Jul 18 15:56 ata-ST4000DM005-2DP166_ZGY0LBRB-part2 -> ../../sde2 lrwxrwxrwx 1 root root 9 Jul 18 15:56 wwn-0x5000c500a3d1d419 -> ../../sde lrwxrwxrwx 1 root root 10 Jul 18 16:01 wwn-0x5000c500a3d1d419-part1 -> ../../sde1 lrwxrwxrwx 1 root root 10 Jul 18 15:56 wwn-0x5000c500a3d1d419-part2 -> ../../sde2 ``` Here we see that we can either use `ata-ST4000DM005-2DP166_ZGY0LBRB` or `wwn-0x5000c500a3d1d419` as symlinks. 3. Edit `/etc/default/hd-idle` to use the symlink you prefer. In my case, I went with the symlink using WWN (unique storage identifier), yet I could have chosen MODEL (device identifier) instead. `HD_IDLE_OPTS='-i 0 -c ata -s 1 -l /var/log/hd-idle.log -a /dev/disk/by-id/wwn-0x5000c500a3d1d419 -i 600'` Or `HD_IDLE_OPTS='-i 0 -c ata -s 1 -l /var/log/hd-idle.log -a /dev/disk/by-id/ata-ST4000DM005-2DP166_ZGY0LBRB -i 600'` ## SCSI response not ok You can find information about the issue here: [SCSI-response-not-ok](https://github.com/adelolmo/hd-idle/wiki/SCSI-response-not-ok) ## License GNU General Public License v3.0, see [LICENSE](https://github.com/adelolmo/hd-idle/blob/master/LICENSE).