On Thu, 11 Apr 2013, James Harper <james.harper@bendigoit.com.au> wrote:
no, it's not. your array scan checks for DISK errors. It does not check for data corruption - THAT is the huge advantage of filesystems like ZFS and btrfs, they can detect and correct data errors
This is the md 'check' function that compares the two copies of the data together. If there was corruption in my RAID1 then it's incredibly unlikely that this corruption would have occurred on both disks and register as a match, at least from a disk based corruption issue.
With RAID-1 the check operation makes the second copy the same as the first in the case of discrepancy, even though the second might have contained the correct data. With Linux Software RAID-5/6 the parity is regenerated if it doesn't match the data - even though with RAID-6 it's possible to regenerate a single corrupted data sector to make the parity match. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/