Re: Small files perform much faster on newly formatted fs?

Dave Chinner
2011-06-09T01:29:11Z

On Wed, Jun 08, 2011 at 08:26:38AM -0400, Norbert Veber wrote:
> On Wed, Jun 08, 2011 at 09:11:10AM +0200, Michael Monnerie wrote:
> > On Dienstag, 7. Juni 2011 Norbert Veber wrote:
> > > 20 seconds vs 3+ minutes?! The only difference I can see is
> > > lazy-count=1 and a larger agcount. Sunit and swidth were also set
> > > automatically by mkfs this time.
> >
> > Then retry mounting the old fs with sunit= and swidth= parameters. Are
> > they on the same disks? What are your disks (number, kind)?
>
> Yes its already mounted this way as I mentioned in my original message:
> /dev/mapper/vg0-shared on /shared type xfs (rw,noatime,sunit=128,swidth=256)

Those mount options are ignored if the filesystem doesn't have the
superblock feature bit set for aligned allocations. A filesystem
with 0/0 for sunit/swidth does not have the superblock bit set....

Cheers,

Dave.
--
Dave Chinner
david@fromorbit.com