[CentOS] Grub configuration from within Windows

Wed Apr 22 21:58:10 UTC 2009
Marko Vojinovic <vvmarko at gmail.com>

My friend uses a typical dual-boot setup (Windows XP and Centos 5.3).
The machine is online 24/7 and he often uses it from a remote location
(Linux via ssh -X, Windows via rdesktop).

The problem is that he wants to be able to remotely configure which of
these two OSes is to be the default on next reboot, so he can switch
from one OS to the other and back remotely. If Linux is up, he just
needs to reconfigure grub.conf, but if Windows is up (and default) he
has no way of accessing grub.conf.

Now, he has several partitions on the drive, some ntfs, some vfat and
some ext3. Is there a clean way of putting grub.conf on a vfat
partition? Is there a way for Windows to have rw access to ext3
filesystem (namely, /)? Is there some other way of handling this
without physical access to the machine while it boots?

I have suggested virtualization of Windows, so he could run them both
concurrently without pain, but for certain (computational performance)
reasons that is not a good option for him --- he wants hard reboots
between OSes.

Any suggestions?

Thanks! :-)
Marko