Request for opinions - gvinum or ccd?

[Ivan Voras]

Sorry to come into the discussion late, but I just want to confirm
something.

The configuration below is a stripe of four components, each of which is
RAIDZ2, right?

If, as was discussed later in the thread, RAIDZ(2) is more similar to
RAID3 than RAID5 for random performance, the given configuration can be
(very roughly, in the non-sequential access case) expected to deliver
performance of four drives in a RAID0 array?

krad wrote:

> zpool create -O compression=lzjb -O atime=off data raidz2 c3t0d0 c4t0d0
> c8t0d0 c10t0d0 c11t0d0 c3t1d0 c4t1d0 c8t1d0 c9t1d0 c10t1d0 c11t1d0 raidz2
> c3t2d0 c4t2d0 c8t2d0 c9t2d0 c11t2d0 c3t3d0 c4t3d0 c8t3d0 c9t3d0 c10t3d0
> c11t3d0 raidz2 c3t4d0 c4t4d0 c8t4d0 c10t4d0 c11t4d0 c3t5d0 c4t5d0 c8t5d0
> c9t5d0 c10t5d0 c11t5d0 raidz2 c3t6d0 c4t6d0 c8t6d0 c9t6d0 c10t6d0 c11t6d0
> c3t7d0 c4t7d0 c9t7d0 c10t7d0 c11t7d0 spare c10t2d0 c8t7d0

>         NAME         STATE     READ WRITE CKSUM
>         archive-2    ONLINE       0     0     0
>           raidz2     ONLINE       0     0     0
>             c3t0d0   ONLINE       0     0     0
>             c4t0d0   ONLINE       0     0     0
>             c8t0d0   ONLINE       0     0     0
>             c10t0d0  ONLINE       0     0     0
>             c11t0d0  ONLINE       0     0     0
>             c3t1d0   ONLINE       0     0     0
>             c4t1d0   ONLINE       0     0     0
>             c8t1d0   ONLINE       0     0     0
>             c9t1d0   ONLINE       0     0     0
>             c10t1d0  ONLINE       0     0     0
>             c11t1d0  ONLINE       0     0     0
>           raidz2     ONLINE       0     0     0
>             c3t2d0   ONLINE       0     0     0
>             c4t2d0   ONLINE       0     0     0
>             c8t2d0   ONLINE       0     0     0
>             c9t2d0   ONLINE       0     0     0
>             c11t2d0  ONLINE       0     0     0
>             c3t3d0   ONLINE       0     0     0
>             c4t3d0   ONLINE       0     0     0
>             c8t3d0   ONLINE       0     0     0
>             c9t3d0   ONLINE       0     0     0
>             c10t3d0  ONLINE       0     0     0
>             c11t3d0  ONLINE       0     0     0
>           raidz2     ONLINE       0     0     0
>             c3t4d0   ONLINE       0     0     0
>             c4t4d0   ONLINE       0     0     0
>             c8t4d0   ONLINE       0     0     0
>             c10t4d0  ONLINE       0     0     0
>             c11t4d0  ONLINE       0     0     0
>             c3t5d0   ONLINE       0     0     0
>             c4t5d0   ONLINE       0     0     0
>             c8t5d0   ONLINE       0     0     0
>             c9t5d0   ONLINE       0     0     0
>             c10t5d0  ONLINE       0     0     0
>             c11t5d0  ONLINE       0     0     0
>           raidz2     ONLINE       0     0     0
>             c3t6d0   ONLINE       0     0     0
>             c4t6d0   ONLINE       0     0     0
>             c8t6d0   ONLINE       0     0     0
>             c9t6d0   ONLINE       0     0     0
>             c10t6d0  ONLINE       0     0     0
>             c11t6d0  ONLINE       0     0     0
>             c3t7d0   ONLINE       0     0     0
>             c4t7d0   ONLINE       0     0     0
>             c9t7d0   ONLINE       0     0     0
>             c10t7d0  ONLINE       0     0     0
>             c11t7d0  ONLINE       0     0     0
>         spares
>           c10t2d0    AVAIL   
>           c8t7d0     AVAIL   
> 
> errors: No known data errors


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