On Tue, Feb 18, 2014 at 2:41 PM, Tomas Vondra <tv@xxxxxxxx> wrote: > On 18.2.2014 02:23, KONDO Mitsumasa wrote: >> Hi, >> >> I don't have PERC H710 raid controller, but I think he would like to >> know raid striping/chunk size or read/write cache ratio in >> writeback-cache setting is the best. I'd like to know it, too:) > > We do have dozens of H710 controllers, but not with SSDs. I've been > unable to find reliable answers how it handles TRIM, and how that works > with wearout reporting (using SMART). AFAIK (I haven't looked for a few months), they don't support TRIM. The only hardware RAID vendor that has even basic TRIM support Intel and that's no accident; I have a theory that enterprise storage vendors are deliberately holding back SSD: SSD (at least, the newer, better ones) destroy the business model for "enterprise storage equipment" in a large percentage of applications. A 2u server with, say, 10 s3700 drives gives *far* superior performance to most SANs that cost under 100k$. For about 1/10th of the price. If you have a server that is i/o constrained as opposed to storage constrained (AKA: a database) hard drives make zero economic sense. If your vendor is jerking you around by charging large multiples of market rates for storage and/or disallowing drives that actually perform well in their storage gear, choose a new vendor. And consider using software raid. merlin -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
