ZFS performance on 7.2-release/amd64 low compared to UFS2 + SoftUpdates

[Freddie Cash]

On Thu, Jun 18, 2009 at 1:29 AM, Pete French <petefrench at ticketswitch.com>wrote:

> > All the ZFS tuning guides for FreeBSD (including one on the FreeBSD
> > ZFS wiki) have recommended values between 64M and 128M to improve
> > stability, so that what I went with. How much of my max kmem is it
> > safe to give to ZFS?
>
> If you are on amd64 then don't tune it, it will tune itself. If you
> are on i386 (or an earlier verions of amd64) then 128M on a 2 gig machine
> should be OK, assuming you have kmem_size_max set to the full 1500 odd.
> Those are numbers which come up time and time again - I ran reliably with
> them for ages, until the latest -STABLE.
>

My "rule of thumb" for 32-bit i386 systems has been to:  - assign half of
RAM to kmem (up to the max of ~1500 on 7.0/7.1)
  - assign half of kmem to zfs_arc_max

So far, for my workloads (nfs/cifs file servers, cups print servers, rsync
servers, kde4 desktop), it's worked well.

-- 
Freddie Cash
fjwcash at gmail.com