zpool scrub speed

devsk devsku at gmail.com
Sat May 7 18:23:33 EDT 2011

Its not reproducible so far (as is typical with intermittent issues)
and I have run scrub before multiple times.

I reduced the ARC to 1.5GB but not to 128M. Previously, very low arc
WAS one of the reasons for lock ups. So, I have never tried that
again. And Brian had put in fixes for actually respecting the ARC
limit in rc4, so I kept it at 2GB because I have 12GB in this box.


On May 7, 3:15 pm, "Fajar A. Nugraha" <l... at fajar.net> wrote:
> On Sun, May 8, 2011 at 5:09 AM, devsk <dev... at gmail.com> wrote:
> > So, it looks like scrub speed is also
> > determined by how much memory is fragmented i.e. on a box which is
> > freshly booted, things are generally faster and as the time goes on
> > and zfs allocates and arc_reclaim eventually reclaims memory
> > repeatedly, things begin to slow down.
> Is the lockup reproducable? Can your repeat the process, but this time
> setting zfs_arc_max and zfs_arc_min to the same value (something like
> 128M or whatever sane value depends on your memory size) thru module
> parameter?
> --
> Fajar

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