Messages in this thread | | | Date | Mon, 12 Apr 2010 10:22:25 +1000 | From | Dave Chinner <> | Subject | Re: Poor interactive performance with I/O loads with fsync()ing |
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On Sun, Apr 11, 2010 at 08:16:09PM +0200, Thomas Gleixner wrote: > On Sun, 11 Apr 2010, Avi Kivity wrote: > > On 04/09/2010 05:56 PM, Ben Gamari wrote: > > > On Mon, 29 Mar 2010 00:08:58 +0200, Andi Kleen<andi@firstfloor.org> wrote: > > > > Ben Gamari<bgamari.foss@gmail.com> writes: > > > > ext4/XFS/JFS/btrfs should be better in this regard > > > > > > > I am using btrfs, so yes, I was expecting things to be better. > > > Unfortunately, > > > the improvement seems to be non-existent under high IO/fsync load. > > > > btrfs is known to perform poorly under fsync. > > XFS does not do much better. Just moved my VM images back to ext for > that reason.
Numbers? Workload description? Mount options? I hate it when all I hear is "XFS sucked, so I went back to extN" reports without any more details - it's hard to improve anything without any details of the problems.
Also worth remembering is that XFS defaults to slow-but-safe options, but ext3 defaults to fast-and-I-don't-give-a-damn-about- data-safety, so there's a world of difference between the filesystem defaults....
And FWIW, I run all my VMs on XFS using default mkfs and mount options, and I can't say that I've noticed any performance problems at all despite hammering the IO subsystems all the time. The only thing I've ever done is occasionally run xfs_fsr across permanent qcow2 VM images to defrag them as the grow slowly over time...
Cheers,
Dave. -- Dave Chinner david@fromorbit.com
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