The controller will report an error, even if the area of the source drive that had the error did not contain data. Scheduling regular verifies will lessen the chance of getting this error.
You can force the rebuild to continue by setting the Overwrite ECC Error policy through 3DM2, 3BM, or CLI, and then rebuilding the unit again. This will cause uncorrectable blocks to be rewritten, but the data may be incorrect. It is recommended that you execute a file system check when the rebuild completes.
For Mac OS X, you can use the First Aid tab in the Disk Utility—select the disk on the left and then click Verify Disk. If verification encounters problems, you can then use the Repair Disk option on the same screen.
