Re: suddenly slow writes on XFS Filesystem

Dave Chinner
2012-05-09T07:04:56Z

On Wed, May 09, 2012 at 01:57:01AM -0500, Stan Hoeppner wrote:
> On 5/7/2012 3:05 PM, Stefan Priebe wrote:
> > Am 07.05.2012 18:36, schrieb Stan Hoeppner:
....
> >> What I would suggest is doing an xfsdump to a filesystem on another LUN
> >> or machine, expand the size of this LUN by 50% or more (I gather this is
> >> an external RAID), format it appropriately, then xfsrestore. This will
> >> eliminate your current free space fragmentation, and the 50% size
> >> increase will delay the next occurrence of this problem. If you can't
> >> expand the LUN, simply do the xfsdump/format/xfsrestore, which will give
> >> you contiguous free space.
> > But this will only help for a few month or perhaps a year.
>
> So you are saying your backup solution will fill up an additional 2.3TB
> in less than a year? In that case I'd say you have dramatically
> undersized your backup storage and/or are not using file compression to
> your advantage. And you're obviously not using archiving to your
> advantage or you'd not have the free space fragmentation issue because
> you'd be dealing with much larger files.
>
> So the best solution to your current problem, and one that will save you
> disk space and thus $$, is to use a backup solution that makes use of
> both tar and gzip/bzip2.

Why use the slow method? xfsdump will be much faster than tar. :)

Cheers,

Dave.
--
Dave Chinner
david@fromorbit.com