Date: Tue, 19 Oct 2004 16:04:57 -0500 From: Mike Horwath <drechsau@Geeks.ORG> To: Kristofer Pettijohn <krishopper@cybernetik.net> Cc: Jo?o Carlos Mendes Lu?s <jonny@jonny.eng.br> Subject: Re: Disk I/O Performance Message-ID: <20041019210457.GH39270@octanews.net> In-Reply-To: <20041019210241.GB80878@cybernetik.net> References: <20041019193501.GC78974@cybernetik.net> <41756EBF.3010008@jonny.eng.br> <20041019210241.GB80878@cybernetik.net>
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On Tue, Oct 19, 2004 at 04:02:41PM -0500, Kristofer Pettijohn wrote: > On Tue, Oct 19, 2004 at 04:45:03PM -0300, Jo?o Carlos Mendes Lu?s wrote: > > I'd say that you have to check which CCD chunk size is best for > > your needs. The manual for vinum recommends avoiding chunk sized to a > > power of two, which is probably the first big mistake of everybody. > > I've tried a wide range of chunk sizes, from 128kB to 64MB.. also have > been avoiding powers of 2. The old idea from someone long ago was to set the stripe size the size of the cylinder block. I found 8MB to be pretty decent, though not perfect. > > Try mounting with option noatime, if you haven't already. And use > > the largest block size possible when formatting. Last time I read about > > there was a limit of 16384, but I would expect better performance for > > large file with 64k blocks (and 8k frags). > > The largest block size is 64k, and I have done that as well. Use this for tunefs - it made a little bit of a difference: tunefs -m 8 -o time /dev/something and make sure you set up the dspool.ctl file correctly because of the change. -- Mike Horwath, reachable via drechsau@Geeks.ORG
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