From mboxrd@z Thu Jan 1 00:00:00 1970 From: Justin Piszcz Subject: Re: stripe_cache_size and performance Date: Mon, 25 Jun 2007 14:21:48 -0400 (EDT) Message-ID: References: <5d96567b0706211242p7f03bd1cw9102ae3e44d67cee@mail.gmail.com> <5d96567b0706220801v76c1c19cl7448050e62e0860b@mail.gmail.com> <467FF1D5.6080007@tmr.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Bill Davidsen Cc: Raz , jnelson-linux-raid@jamponi.net, linux-raid@vger.kernel.org List-Id: linux-raid.ids It was going with 32k just REALLY slow, will use 128k+ 1073737728 2007-06-25 13:07 Bonnie.5178.000 On Mon, 25 Jun 2007, Justin Piszcz wrote: > > > On Mon, 25 Jun 2007, Justin Piszcz wrote: > >> >> >> On Mon, 25 Jun 2007, Bill Davidsen wrote: >> >>> Justin Piszcz wrote: >>>> I have found a 16MB stripe_cache_size results in optimal performance >>>> after testing many many values :) >>> >>> We have discussed this before, my experience has been that after 8 x >>> stripe size the performance gains hit diminishing returns, particularly >>> for typical write instead of big aligned blocks, possibly with O_DIRECT. I >>> would suggest that as a target even on a low memory machine. >>> >>> Do your tests show similar? I was only able to test three and four drive >>> setups using dedicated drives. >>> >>> -- >>> bill davidsen >>> CTO TMR Associates, Inc >>> Doing interesting things with small computers since 1979 >>> >> >> I will re-benchmark with my current setup, however: >> >> Each of these are averaged over three runs: >> >> 128k_stripe: 69.2MB/s >> 256k_stripe: 105.3MB/s >> 512k_stripe: 142.0MB/s >> 1024k_stripe: 144.6MB/s >> 2048k_stripe: 208.3MB/s >> 4096k_stripe: 223.6MB/s >> 8192k_stripe: 226.0MB/s >> 16384k_stripe: 215.0MB/s >> >> This was with 6 sata disks. >> >> Justin. >> - >> To unsubscribe from this list: send the line "unsubscribe linux-raid" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > > I set it to 32 and my machine has several hung processes in D state, not > good. I will start with 128k and up. > > Justin. > - > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >