Re: Installing grub onto a system with XFS root fs

[Jason White <jason@jasonjgw.net>]

On Sun, Dec 16, 2007 at 07:07:11PM -0600, Eric Sandeen wrote:
 
> Hard to say - in a nutshell, grub just sucks w.r.t. how it (ab)uses the
> filesystem it's trying to install on.
> 
> In some invocations, it actually writes directly to the block device
> *while it is mounted* - this leads to data corruption and/or filesystem
> corruption.
> 
> In other cases, in a "verification" phase, it tries to directly read
> filesystem structures off the disk *while it is mounted* after a couple
> of wishful sync; sync;'s - this often can lead to a grub hang when it
> goes off in the weeds on inconsistent disk data that it finds.
> 
> I think various distros have tried to hack around these problems in
> different ways; the freeze above is probably an effort to coalesce the
> filesystem before grub goes groveling around the disk to verify what it
> just wrote(!).
> 

Thanks for the background. The most up to date bug report and discussion I
could find is here:
https://bugs.launchpad.net/debian/+source/grub/+bug/8058
(for Ubuntu).

There are also Debian bugs for this, such as
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=239111

Manually unfreezing the file system with xfs_freeze -u /
worked for me on one machine. (This was done while grub-install was executing,
after it executed xfs_freeze).