Date: Mon, 02 May 2005 08:16:12 -0500 From: Eric Anderson <anderson@centtech.com> To: Poul-Henning Kamp <phk@phk.freebsd.dk> Cc: freebsd-performance@freebsd.org Subject: Re: Very low disk performance on 5.x Message-ID: <4276281C.6060209@centtech.com> In-Reply-To: <17442.1115039706@critter.freebsd.dk> References: <17442.1115039706@critter.freebsd.dk>
next in thread | previous in thread | raw e-mail | index | archive | help
Poul-Henning Kamp wrote: > In message <427626DC.5030702@centtech.com>, Eric Anderson writes: > > >>Don't mean to be terse here, but I'm talking about the same test done an >>two different RAID5 configurations, with different disks, and not just >>me - other users in this very thread see the same issue.. > > > Uhm, if you are using RAID5 and your requests are not aligned and > sized after the RAID5 you should *expect* read performance to be poor. > > If you your request ends up accessing two different blocks even just > once per stripe, this totally kills performance. Wouldn't this be a problem for writes then too? -- ------------------------------------------------------------------------ Eric Anderson Sr. Systems Administrator Centaur Technology A lost ounce of gold may be found, a lost moment of time never. ------------------------------------------------------------------------
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4276281C.6060209>