jenksdrummer
Patron
- Joined
- Jun 7, 2011
- Messages
- 250
I've generally looked at RAID6/60 as the 'correctable' RAID; that if there is a bit-rot/flip that happens in the data or in one of the parity, between the original data and the two parity calculations a corrective action can be performed to put that data back to it's original value (or the parity can be updated). I've viewed RAID10 as not being able to do that...basically it can detect that the data is a mismatch between the mirrors and it's more or less a best-guess as to which is the correct bit value.
That's probably incorrect; but that's just what I've gone with and my preference for RAID6/60 (outside of the N+2 vs N/2 and that you can lose any 2 disks vs any 1 disk per mirror pair parts) - though performance is performance...
** But, my point is with ZFS, does that make that thought moot? Without researching much more on the topic, I believe that on top of all of it, there is a checksum that is also written per block, which if it fails the checksum, then the checksum can be compared to the data either in parity or on the mirror, and the mis-match value corrected. Is this accurate?
That's probably incorrect; but that's just what I've gone with and my preference for RAID6/60 (outside of the N+2 vs N/2 and that you can lose any 2 disks vs any 1 disk per mirror pair parts) - though performance is performance...
** But, my point is with ZFS, does that make that thought moot? Without researching much more on the topic, I believe that on top of all of it, there is a checksum that is also written per block, which if it fails the checksum, then the checksum can be compared to the data either in parity or on the mirror, and the mis-match value corrected. Is this accurate?