On Wed, Jul 18, 2012 at 07:01:48AM -0400, Jaromir Capik wrote:
Hello.
I'd like to ask you to implement the following ...
The current RAID1 solution is not robust enough to protect the data
against random data corruptions. Such corruptions usually happen
when an unreadable sector is found by the drive's electronics
and when the drive's trying to reallocate the sector to the spare area.
There's no guarantee that the reallocated data will always match
the original stored data since the drive sometimes can't read the data
correctly even with several retries. That unfortunately completely masks
the issue, because the sector can be read by the OS without problems
even if it doesn't contain correct data. Would it be possible
to implement chunk checksums to avoid such data corruptions?
If a corrupted chunk is encountered, it would be taken from the second
drive and immediately synced back. This would have a small performance
and capacity impact (1 sector per chunk to minimize performance impact
caused by unaligned granularity = 0.78% of the capacity with 64k chunks).
Please, let me know if you find my request reasonable or not.
I believe alternative to that is implemented via the Linux RAID MD badblock feature.
best regards
keld