Re: zfs performance

Frank Cusack wrote:
On Sun, 24 Jun 2007 11:51:44 +1200 Ian Collins <ian-news@xxxxxxxxxxx> wrote:
Frank Cusack wrote:
On Sat, 23 Jun 2007 18:34:11 +0100 Michael Pye <michael@xxxxxxxxxx> wrote:
V100, one ide disk, all slices ufs. I altered one slice to use zfs,
the slice houses the cache directory for squid proxy
server. Performance was much worse than using ufs which I wasn't
expecting. iostat -xn 1 showed %busy as between 0-40 whilst ufs was
between 0-5.

Is this because the disk is a mixture of ufs and zfs, is zfs not
recommended to be used for a single slice when other slices are ufs on
a single disk ?
Most likely, yes.
Not really, all that happens in this case is ZFS is unable to enable the
drive's write cache.

Which is a significant performance penalty, is it not?

Apparently not, at least according to recent postings on zfs-discuss.
It would only impact ZFS performance relative to ZFS on a whole drive,
not ZFS compared to UFS which also runs with the cache off.

--
Ian Collins.
.

Relevant Pages

  • Re: zfs performance
    ... the slice houses the cache directory for squid proxy ... Is this because the disk is a mixture of ufs and zfs, ... recommended to be used for a single slice when other slices are ufs on ...
    (comp.unix.solaris)
  • zfs performance
    ... V100, one ide disk, all slices ufs. ... I altered one slice to use zfs, the slice houses the cache directory for squid proxy server. ... Performance was much worse than using ufs which I wasn't expecting. ...
    (comp.unix.solaris)
  • Re: zfs performance
    ... slice houses the cache directory for squid proxy server. ... much worse than using ufs which I wasn't expecting. ... Is this because the disk is a mixture of ufs and zfs, ... requested block; the UFS blocks in a cylinder are AFAIR written in ...
    (comp.unix.solaris)
  • Re: zfs and disk write cache
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  • Re: zfs and disk write cache
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    (freebsd-current)