On Fri, Feb 03, 2012 at 12:50:17PM -0600, Eric Sandeen wrote:
> On 2/3/12 8:39 AM, Marcos Mello wrote:
> > Eric Sandeen <sandeen <at> sandeen.net> writes:
> >> In general there is no problem with xfs on a root partition. However, the
> > installer
> >> may not make it easy or available for you.
> >> (I never use xfs for /boot though, I don't trust grub enough for that
> > honestly).
> >> -Eric
> > Same thing on Fedora 16. Let's hope some day Anaconda will change that.
> F16 prevents it? I didn't see it in the upstream tree. That should
> not be so. :/
> > About GRUB with a XFS /boot the problem was with GRUB Lagacy, wasn't it?
> > Or GRUB2 is still buggy?
> I have no idea, actually. I delved into grub a bit, it was disturbing
> enough that I have not tried to look at grub2. :)
Certainly the problem exists with legacy grub - it assumes that it
can write to the first sector or any disk or partition which
overwrites the XFS superblock...
The grub2 manual:
indicates that if you are using BIOS/MBR based booting, then grub2
still writes to the first sector of the partition that contains the
grub directory to install the stage 1.5 loader. Indeed:
On PC BIOS systems, this image is the first part of GRUB to start.
It is written to a master boot record (MBR) or to the boot sector of
a partition. Because a PC boot sector is 512 bytes, the size of this
image is exactly 512 bytes.
The sole function of boot.img is to read the first sector of the
core image from a local disk and jump to it. Because of the size
restriction, boot.img cannot understand any file system structure,
so grub-setup hardcodes the location of the first sector of the core
image into boot.img when installing GRUB. "
IOWs, you have to treat grub2 identically to legacy grub in that it
thinks it owns the first sector of any partition on the disk.
Therefore, you need a separate /boot partition that is not formated
with XFS to be safe.
There's a reason I went back to using LILO....