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Date: Thu, 18 Jun 2009 00:05:12 -0700 (PDT)
From: Simun Mikecin <numisemis@yahoo.com>
To: Dan Naumov <dan.naumov@gmail.com>
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Cc: freebsd-fs@freebsd.org
Subject: Re: ZFS performance on 7.2-release/amd64 low compared to UFS2 +
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Dan Naumov wrote:

> All the ZFS tuning guides for FreeBSD (including one on the FreeBSD
> ZFS wiki) have recommended values between 64M and 128M to improve
> stability, so that what I went with. How much of my max kmem is it
> safe to give to ZFS?


On amd64 since 7.2-RELEASE manually adjusting kmem map or arc size is not necessary any more (see /usr/src/UPDATING) for stability. But if you like you can still do it.
If you want to use ZFS allot I suggest to use latest 7-STABLE (which has ZFS v13, more stable, more bugs resolved). amd64 of course. For i386 it would be better to use UFS+SU (for SCSI) or UFS+gjournal (for ATA).

btw. turning on compression on ZFS filesystems might actually increase it's performance that is seen by benchmark programs.