Re: XFS on root

[Adam Wilson <moxalt@riseup.net>]

On Mon, 29 Feb 2016 11:28:57 -0600 Glenn Holmer <shadowm@lyonlabs.org>
wrote:

> On 02/28/2016 01:31 PM, mj wrote:
> > On 02/28/2016 03:34 PM, Adam Wilson wrote:
> >> Let me get this straight- /boot on XFS, with GRUB, working
> >> flawlessly?
> > 
> > I think we have been running root xfs, without a seperate boot
> > partition for ages. This has been working at least since wheezy,
> > but I guess even earlier.
> > 
> > Just try it.
> 
> I have machines with multiple operating systems, and use a "master"
> GRUB in its own small partition with the boot code in the MBR, and a
> "slave" GRUB embedded in each operating system's boot partition. I
> don't know if this is still true (the message is quite old), but it's
> why I've always used a separate ext2 /boot partition in that scenario.
> 
> http://www.mail-archive.com/bug-grub@gnu.org/msg10770.html
> 
> "As we all know, you cannot install grub into an XFS partition because
> the XFS superblock is in sector 0 of the partition."

I'm pretty sure this only holds true for LILO now, according to the
official XFS FAQ
(http://xfs.org/index.php/XFS_FAQ#Q:_Does_GRUB_work_with_XFS.3F).
Concerning GRUB, it has this to say:

> There is native XFS filesystem support for GRUB starting with version
> 0.91 and onward. Unfortunately, GRUB used to make incorrect
> assumptions about being able to read a block device image while a
> filesystem is mounted and actively being written to, which could
> cause intermittent problems when using XFS. This has reportedly since
> been fixed, and the 0.97 version (at least) of GRUB is apparently
> stable.

"apparently stable" wasn't good enough for me- GRUB on XFS support is
sketchy at best, so to be on the safe side I just used ext2 for boot.

The only downside to this is that I had to forgo a separate /var
partition, which is another thing I like to do, using only primary
partitions under MBR (as opposed to logical, which I have an irrational
dislike for).