On Thu, Mar 25, 2010 at 12:44 PM, Richard Elling <richard.ell...@gmail.com>wrote:
> On Mar 25, 2010, at 12:10 PM, Freddie Cash wrote: > > > On Thu, Mar 25, 2010 at 11:47 AM, Bruno Sousa <bso...@epinfante.com> > wrote: > > What do you mean by "Using fewer than 4 disks in a raidz2 defeats the > purpose of raidz2, as you will always be in a degraded mode" ? Does it means > that having 2 vdevs with 3 disks it won't be redundant in the advent of a > drive failure? > > > > raidz1 is similar to raid5 in that it is single-parity, and requires a > minimum of 3 drives (2 data + 1 parity) > > no. raidz requires a minimum of 2 drives: data + parity > > > raidz2 is similar to raid6 in that it is double-parity, and requires a > minimum of 4 drives (2 data + 2 parity) > > Similarly, raidz2 requires 3 drives: data + 2 parity > > Coolio. Learn something new everyday. One more way that raidz is different from RAID5/6/etc. So, is it just a "standard" that hardware/software RAID setups require 3 drives for a RAID5 array? And 4 drives for RAID6? -- Freddie Cash fjwc...@gmail.com
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