On 2012-11-14 18:05, Eric D. Mudama wrote:
On Wed, Nov 14 at  0:28, Jim Klimov wrote:
All in all, I can't come up with anything offensive against it quickly
;) One possible nit regards the ratings being geared towards 4KB block
(which is not unusual with SSDs), so it may be further from announced
performance with other block sizes - i.e. when caching ZFS metadata.


Would an ashift of 12 conceivably address that issue?


Performance-wise (and wear-wise) - probably. Gotta test how bad it is
at 512b IOs ;) Also I am not sure if ashift applies to (can be set for)
L2ARC cache devices...

Actually, if read performance does not happen to suck at smaller block
sizes, ashift is not needed - the L2ARC writes seem to be streamed
sequentially (as in an infinite tape) so smaller writes would still
coalesce into big HW writes and not cause excessive wear by banging
many random flash cells. IMHO :)

//Jim
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