RAID6 can lose any 2 drives and still operate, so any 3 drives will cause complete failure. RAID10 will fail in as few as 2 drive failures, or as much as half of the array + 1.
RAID10 has a better best case scenario failure rate, but a worse worst case scenario than RAID6. It may be unlikely, perhaps even very unlikely, for matched pairs to fail together, it still must be considered. This limitation can be mitigated with hot spares since they decrease the window of time the array is in a degraded state. Also since RAID10 has a much quicker rebuild time, the window will be really small with a hot spare or two. On Tue, Mar 12, 2013 at 1:10 PM, Nicholas Leippe <[email protected]> wrote: > On Tue, Mar 12, 2013 at 1:06 PM, Lonnie Olson <[email protected]> wrote: >> Important thing to consider is Murphy's law. The minimum number of >> disk failures to destroy your whole array. In RAID6, it's 3 disks. >> In RAID10, it's 2 disks. Obviously this would have to be a matched >> pair, but s#!* happens. > > I haven't studied raid6--how flexible is it regarding which 3 disks > can fail, compared to raid10's up to half excluding both from a > mirrored pair? > > /* > PLUG: http://plug.org, #utah on irc.freenode.net > Unsubscribe: http://plug.org/mailman/options/plug > Don't fear the penguin. > */ /* PLUG: http://plug.org, #utah on irc.freenode.net Unsubscribe: http://plug.org/mailman/options/plug Don't fear the penguin. */
