|There are unfortunately several problems with the XFS support included in the 18.104.22.168 kernel included with sarge. This is of course used by the “linux26” flavour in the installer, this is not however the default since sarge is shipping with 2.4.27 as the default kernel. Many users however will want to use the 2.6 variant for improved hardware support.
Diagnosis of the problem is proving somewhat difficult, the main symptoms are kernel panics and lock ups when putting the file system under moderate load. In my experience this led to a corrupted journal which xfs_repair was forced to throw it away. Not particularly nice since this was in the middle of a large collection of package upgrades. Even if you get away with your metadata in a reasonable condition your data may well still be hosed, if you don’t unmount correctly, since XFS does not write data to disk immediately, it instead waits to build up some idea of how large the file will be and then allocates one nice large contiguous extent for the file (delayed allocation). (Of course since your disks are going to write caching anyway that point is pretty moot.) To prevent information leakage any extents belonging to a file that have not been completely written out are filled by null bytes. If this file happens to be the libc.so.6 that most of your semi-installed userland wants to use then you are somewhat stuffed. Some interesting bugs on this: #274988, #278161, and #292290.
There are certainly no plans to replace 2.6.8 in the sarge installer since this would require a significant amount of work at a really bad time. You should aim to immediately upgrade your kernel as soon as possible. With a bit of cunning you can even do this before your first boot. Simply switch to spare virtual terminal, chroot into the target, mount /proc, add a source to the sources list and then install the new kernel, update your boot loader and you’re done.