On Sat, 14 May 2011 21:58:21 +1000
NeilBrown [off-list ref] wrote:

If you don't have ext3, then you probably need to backup and restore - I
don't think other filesystems support shrinking, but I could be wrong.

Well, ext4 does support shrinking as well.

And btrfs, it has both online shrinking and growing.

XFS, JFS can only be grown, not shrinked.

-- 
With respect,
Roman