Re: Poor disk performance in NetBSD DomU, again

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Tue, May 13, 2014 at 01:47:46PM -0400, Yi Qiao wrote:
> On Tue, May 13, 2014 at 1:33 PM, Manuel Bouyer 
> <bouyer%antioche.eu.org@localhost> wrote:
> > On Tue, May 13, 2014 at 01:29:23PM -0400, Yi Qiao wrote:
> >> Hi Manuel
> >>
> >>   Sorry about that. It's all PV guests. And I don't think partition
> >> alignments is the dominating issue here since after each experiment, I
> >
> > it can, depending on how the virtual disk is partitionned in the guest.
> 
> I see. For the NetBSD installs, I simply partitioned xvda into / with
> 9728M and swap with 512M. For the FreeBSD install, I accepted the
> default partition scheme, which I think is a very small boot partition
> at the beginning, 9G ish in the middle for /, and 512M as swap. For
> Ubuntu, I let the installer create it's own lvm.
> 
> The only straightforward way I can think to test the theory right now
> is to change the order of the root and swap partitions during a NetBSD
> install. However since the swap is only 512M, I doubt it will make a
> noticeable difference.

what's important is the root's partition start. By default it can
be 63 or 2048 sectors, and this can make a difference with recent
disks.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--