Date: Mon, 10 Jan 2011 13:33:51 +0000 From: Bruce Cran <bruce@cran.org.uk> To: Ivan Voras <ivoras@freebsd.org> Cc: freebsd-performance@freebsd.org Subject: Re: Phoronix comparision of HAMMER, UFS, ZFS, EXT3, EXT4, Btrfs Message-ID: <20110110133351.00007c8b@unknown> In-Reply-To: <igf0k0$hro$1@dough.gmane.org> References: <4D26FBD3.20307@quip.cz> <448737.83863.qm@web110508.mail.gq1.yahoo.com> <52B3EE9B-9B4A-4F96-ADE3-83F56135183D@moneybookers.com> <igev84$8si$1@dough.gmane.org> <20110110130703.000047b7@unknown> <igf0k0$hro$1@dough.gmane.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, 10 Jan 2011 14:12:32 +0100 Ivan Voras <ivoras@freebsd.org> wrote: > I've also noticed it is bursty - this can be moderated by tuning > vfs.zfs.txg.timeout and vfs.zfs.vdev.max_pending. But I think you > must agree that 210 MB/s on a single drive looks impossible :) I get > that much in a SAS RAID-10 configuration. Exactly: since the disk obviously can't write at 210MB/s (115 seems to be about its maximum) ZFS is buffering the data and then has to spend time flushing it to disk during which time it can't accept any new IO requests. -- Bruce Cran
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20110110133351.00007c8b>