[OmniOS-discuss] Status of TRIM support?

[Saso Kiselkov]

On 5/28/14, 3:51 PM, Dan Swartzendruber wrote:
> (merging comments to Saso and Jim)
> 
> I don't think I mentioned my environment - if not, my apologies.  This is
> a SOHO/Lab setup, so things like zeusram are non-starters.  The basic
> network infrastructure is gigabit, so iSCSI ZIL would suck badly, I
> suspect.  As far as over-provisioning the 840PRO, I have it sliced for
> 16GB.  Once it's been running for awhile, I will re-run the disk
> benchmark.  I understand the 840PRO doesn't have a supercap - this was
> basically just a performance analysis to see how it stacks up compared to
> sync=disabled and on-pool ZIL.  If I go this route, I will need to look
> for a decent/affordable unit with supercap.  One other test I can try is
> with a 15K 76GB SAS 2.5-inch drive I salvaged from a dead server.  It
> should have about 1/2 the latency of a 7200rpm sata drive, and if so would
> get me up to about 40MB/sec, which is still not good, but better than
> on-pool ZIL.  I'll find out later.  I have googled a fair amount and there
> seems to be 'work in progress' for TRIM support for ZoL and illumos, but
> no real indication I could find as to when either might support it.

If you want IOPS performance out of HDDs, short-stroke the hell out of
them. The 76 GB drive should be reduced to something like 2-4 GB so that
only the outermost tracks are used. But a good power-protected SSD can
nowadays be had for relatively little and will absolutely crush the
short-stroked HDD in throughput.

Cheers,
-- 
Saso