Date: Thu, 22 Mar 2012 00:33:25 -0000 From: "Steven Hartland" <killing@multiplay.co.uk> To: "andy thomas" <andy@time-domain.co.uk>, <freebsd-fs@freebsd.org> Subject: Re: ZFS read/write performance slows with time Message-ID: <54245FA2BA39427993410B7363178EE7@multiplay.co.uk> References: <Pine.GSO.4.64.1203212341010.5175@mail.time-domain.co.uk>
next in thread | previous in thread | raw e-mail | index | archive | help
----- Original Message -----
From: "andy thomas" <andy@time-domain.co.uk>
To: <freebsd-fs@freebsd.org>
Sent: Wednesday, March 21, 2012 11:56 PM
Subject: ZFS read/write performance slows with time
>A server running 64-bit FreeBSD 8.0 boots from a SATA disk and then mounts
> a ZFS mirror consisting of two SAS disks plus one spare. Immediately after
> booting, the filesystem is fast and responsive and 'zpool iostat -v tank'
> reports read and write disk bandwidths of over 22 MB.
>
> But over a period of time, this performance begins to deteriorate and
> after 180 days of uptime this server, which is running mail, samba and
> webmail servers in 3 separate jails, really struggles especially the IMAP
> daemon. zpool iostat -v reports a maximum read bandwidth of around 2MB and
> a write bandwidth of 143 KB maximum. Rebooting the system restores normal
> performance but the cycle gradually repeats itself.
>
> I can't see anything wrong in any log and the system has 12 GB of memory
> and a 2 Ghz quad-core Xeon CPU so it isn't under-resourced. At boot time
> ZFS reports its version as being 13 - could the problem be due to a memory
> leak or some other issue with early versions of ZFS that have since been
> fixed in later FreeBSD releases?
There are known issues with the code in 8.0 which could easily cause the
behaviour you describe, I'd recommend upgrading to 8-STABLE or 8.3-RELEASE
when its done as that brings in a large amount of fixes for ZFS including
v28 support iirc.
Regards
Steve
================================================
This e.mail is private and confidential between Multiplay (UK) Ltd. and the person or entity to whom it is addressed. In the event of misdirection, the recipient is prohibited from using, copying, printing or otherwise disseminating it or any information contained in it.
In the event of misdirection, illegible or incomplete transmission please telephone +44 845 868 1337
or return the E.mail to postmaster@multiplay.co.uk.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?54245FA2BA39427993410B7363178EE7>