Need to update for XFS crc=1 (non-default) on-disk format change
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
grub2 (Fedora) |
Fix Released
|
Undecided
|
|||
grub2 (Ubuntu) |
Fix Released
|
Low
|
Unassigned |
Bug Description
Filing a note here in case I forget later.
It looks like GRUB (2.02-beta2-15) in 14.10 doesn't support XFS's new on-disk metadata format that has CRCs. (rationale: https:/
mkfs.xfs -m crc=1,finobt=1 /dev/sdXY creates an XFS with the new on-disk format. This is NOT the default, and probably won't be until kernel support for it has been in distros for a while.
redhat bug with some patches from Dec 2014:
https:/
I haven't yet dug up any changelogs about those patches getting merged into GRUB's upstream git repo.
If there's a PPA, or an easy way to build a .deb from git master (or some other way I can easily test git master on an Ubuntu system), I'd be interested and willing to test this.
Testing confirms that xfs crc support was the issue. I made two plain non-MD partitions to take that out of the equation. I formatted one with XFS defaults, and the other with XFS crc. I copied my fresh ubuntu install into each one. I did grub-install /dev/sda while chrooted into the non-crc xfs, and grub-install /dev/sdb in the CRC one. Booting from sda worked fine.
Booting from sdb (I can tell them apart in the bios boot menu easily, because they're not the same make), I was dropped into the grub rescue shell. I could use grub's ls to see data on the non-crc partition, but not on the crc partition. So it's clear that GRUB doesn't understand the new XFS metadata v5 format.
description: | updated |
Changed in grub2 (Fedora): | |
importance: | Unknown → Undecided |
status: | Unknown → Fix Released |
From the XFS list:
> Just a heads-up: GRUB currently doesn't work on a CRC enabled
> file-system. It will print the following error message:
> "not a correct XFS inode"
This format is still WIP upstream, but we should probably have the issue on the RHEL7 radar since we plan to default to XFS even for /boot.
A simple workaround would be to not enable CRCs for the root fs; this may be done by default in any case.
So this bug may be a WONTFIX or NOTABUG, but I figured we should at least log the issue.
Thanks,
-Eric