> From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss-
> boun...@opensolaris.org] On Behalf Of Fajar A. Nugraha
> So my
> suggestion is actually just present one huge 25TB LUN to zfs and let
> the SAN handle redundancy.

Oh - No....

Definitely let zfs handle the redundancy.  Because ZFS is doing the 
checksumming, if it finds a cksum error, it needs access to the redundant copy 
in order to correct it.  If you let the SAN handle the redundancy, then zfs 
finds a cksum error, and your data is unrecoverable.  (Just the file in 
question, not the whole pool or anything like that.)

The answer to Morris's question, about size of LUNs and so forth...  It really 
doesn't matter what size the LUNs are.  Just choose based on your redundancy 
and performance requirements.  Best would be to go JBOD, or if that's not 
possible, create a bunch of 1-disk volumes and let ZFS handle them as if 
they're JBOD.

Performance is much better if you use mirrors instead of raid.  (Sequential 
performance is just as good either way, but sequential IO is unusual for most 
use cases. Random IO is much better with mirrors, and that includes scrubs & 

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