Defragging XFS File Systems

[Stewart Smith]

On Mon, 6 Jun 2011 22:52:48 -0500, Kenneth Emerson <kenneth.emerson at gmail.com> wrote:
> I hadn't given much thought to fragmentation of my TV recordings volume
> (XFS) until reading through some MythTV-users threads recently that
> mentioned how fragmented an XFS file system could become.  After running
> xfs_db, I found out that my fs appeared to be quite bad:

MythTV can end up with fragmentation on XFS due to an fsync() call that
attempts to work raound limitations in ext3.

Workarounds include:
- allocsize mount parameter
- patch mythtv source not to fsync (you could easily write a patch that
only did fsync if not xfs... I've been meaning to do this for
years... not enough hours in day).
- run mythbackend with libeatmydata, thus disabling the fsync

-- 
Stewart Smith