Poor ZFS performance

[Mel Flynn]

On Monday 04 May 2009 02:07:41 nf wrote:
> On Sat, May 2, 2009 at 7:22 PM, Frederique Rijsdijk
>
> <frederique at isafeelin.org> wrote:
> > nf wrote:
> >> 733843456 bytes transferred in 61.124812 secs (12005656 bytes/sec)
> >
> > That is very low. I get about 60MB/sec in this way. Adding bs=1m it'll go
> > up to 240MB/sec even (raidz1 with 4*1TB).
> >
> > Could you show top -S ?
>
> I will, the next time I experience the issue.
>
> I had already rebooted the box, which immediately alleviated the
> issue. I can only presume, at this point, that it seems to have been
> related to the 2gb of allocated/active memory shown by top. I had no
> memory intensive apps running, merely an idle lighttpd, mysqld, and
> rtorrent (which only occupied about 90mb).

There's a thread or 2 on -current list about ZFS arc cache growth, that you 
may or may not be seeing as well.

<http://www.freebsd.org/cgi/mid.cgi?id=20090417145024.205173ighmwi4j0o@webmail.leidinger.net&db=mid>
-- 
Mel