partially degraded raid 6 _IS_ vunerable to partial writes on power failure
Posted Sep 4, 2009 23:32 UTC (Fri) by giraffedata
In reply to: partially degraded raid 6 _IS_ vunerable to partial writes on power failure
Parent article: Ext3 and RAID: silent data killers?
But you don't have to build a RAID6 array that way. Ones I've looked at use a journaling scheme to provide atomic parity update. No matter where you get interrupted in the middle of updating a stripe, you can always get back the pre-update parity-consistent stripe (minus whatever 1 or 2 components that might have died at the same time).
I suspect Linux 'md' doesn't have the resources to do this feasibly, but a SCSI RAID6 unit probably would. I don't expect there's much market for the additional component loss protection of RAID6 without getting the interrupted write protection too.
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