Date: Sun, 18 Mar 2007 12:51:17 +0100 From: Axel Rau <Axel.Rau@Chaos1.DE> To: freebsd-database@freebsd.org, FreeBSD AMD list <freebsd-amd64@freebsd.org> Subject: Re: New Opteron box, dedicated to PostgreSQL Message-ID: <7489C7AA-BD33-4144-ABD4-73338CD5C7C7@Chaos1.DE> In-Reply-To: <111EFCD1-0B88-4646-BCF5-B13D1F3BBCB0@khera.org> References: <8CDBEAF9-0945-4CD2-89C4-58AA63850ECC@Chaos1.DE> <b41c75520703160417w672a6b92x38cac65001bc3ea1@mail.gmail.com> <111EFCD1-0B88-4646-BCF5-B13D1F3BBCB0@khera.org>
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Am 16.03.2007 um 21:04 schrieb Vivek Khera: > > On Mar 16, 2007, at 7:17 AM, Claus Guttesen wrote: > >>> while configuring my 1st PostgreSQL box with dual Opterons (2212) on >>> FreeBSD, I have some questions: >>> >>> 3. What are the recommendations for tuning I/O)? >>> - setting sysctl vfs.read_max to 16 or 32 >>> - rebuilding the relevant filesystem with 32K blocks and 4K >>> frags >>> Are these reliable? >> >> The following were suggetions from Vivek Khera: > > I've recently bumped the shmall and shmmax on my dual opteron with > 16GB of RAM, and increased correspondingly the shared buffers. > > The max shmall you can set on freebsd (at least 6.1) is 2147483647, > so I set shmall to 524288 to correspond. This supports 250000 > shared buffers and 100 max connections. Might support more, but > definitely not 260000. This box will start with 8GB of RAM, should also support 100 connections, so I will try half of your values (pretty your settings posted by Claus Guttesen <kometen@gmail.com>). > > I'm also using vfs.read_max=32 but I haven't really tested if it > makes a big difference in formal benchmarks. > > The other day I was having some I/O overload, so I tried setting > vfs.hirunningspace to 3K but it didn't solve my immediate problem. > I've left that setting for now. Doesn't seem to really make a big > difference. > > I find that the adaptec 2230SLP RAID controllers are not able to > keep up with my load, but the LSI 320-2X is. I'm currently > investigating external arrays attached via fibre for some boost. This box will have an Areca ARC-1261ML (RAID 1 for OS and WAL, RAID 0 with 7xRAID1 for pg_data). Any hints beside the usual partition alignment and stripe size of 128kB ? Do you use ufs2 with softupdates? regards, Axel --------------------------------------------------------------------- Axel Rau, ☀Frankfurt , Germany +49 69 9514 18 0help
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