Date: Tue, 12 Feb 2008 10:42:47 +0000 From: "Joao Barros" <joao.barros@gmail.com> To: "Alexey Tarasov" <me@lexasoft.ru> Cc: Niki Denev <nike_d@cytexbg.com>, current@freebsd.org Subject: Re: Disappointing speed with ZFS Message-ID: <70e8236f0802120242y7f6d8ec9xed9824255210a453@mail.gmail.com> In-Reply-To: <2e77fc10802111337j45915422v42c098a1574406fb@mail.gmail.com> References: <9DA6FFCD-11DB-4580-9314-52B0885351D8@lexasoft.ru> <fopmlp$qeh$1@ger.gmane.org> <50186FCD-F67F-4144-BDF1-FB9A7F9AAB64@lexasoft.ru> <2e77fc10802111337j45915422v42c098a1574406fb@mail.gmail.com>
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On Feb 11, 2008 9:37 PM, Niki Denev <nike_d@cytexbg.com> wrote: > On Feb 11, 2008 7:05 PM, Alexey Tarasov <me@lexasoft.ru> wrote: > > I've done similar tests on the other machine, and all looks fine. > > > > But why on this machine ZFS works slower than UFS? When I make UFS > > file system on the same disk, rtorrent hashing works 10 times faster. > > And while hashing, HDD is used three times intensively with ZFS > > (noticed by flashing LED). > > > > I have an amd64 Core2Duo processor, 4 Gb of RAM, what is not enough > > for ZFS? > > > > What kernel tuning can help me? > > > > > > What happens when you disable ZFS prefetching by putting : > vfs.zfs.prefetch_disable=1 > in your /boot/loader.conf? > This would be my recommendation as well. I had to disable prefetch to be able to play video files(1.1GB ~43mins) from a 4 disk raidz without jitter. I can even play 2 video files concurrently now :) Try and show us the results. -- Joao Barros
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