grub-probe fail when fs is larger than 2tb

[Elias Abacioglu]

don't really know if this is a resize2fs problem or a grub problem.
But we discovered it when trying to cloud-init bootstrap a node with larger than 2 TB disk.

Create a virtual or a physical node with more than 2TB disk.
install ubuntu cloud image on disk.
boot and let cloud init run it's course, after that grub2 os-probe will fail with this error message:
grub-probe: error: unknown filesystem.

Have tested this in both trusty and xenial

Update, adding parted info
# parted -l
Model: Virtio Block Device (virtblk)
Disk /dev/vda: 2255GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:

Number Start End Size File system Name Flags
 1 1049kB 33.6MB 32.5MB grub bios_grub
 2 33.6MB 8590MB 8556MB linux-swap(v1) swap
 3 8590MB 2255GB 2246GB ext4 cloudimg-rootfs boot, esp

[Elias Abacioglu (raboo)]

here is the manual reproduction

root@ubuntu:~# /etc/kernel/postinst.d/zz-update-grub 4.4.0-64-generic /boot/vmlinuz-4.4.0-64-generic
Generating grub configuration file ...
Warning: Setting GRUB_TIMEOUT to a non-zero value when GRUB_HIDDEN_TIMEOUT is set is no longer supported.
Found linux image: /boot/vmlinuz-4.4.0-64-generic
Found initrd image: /boot/initrd.img-4.4.0-64-generic
Found linux image: /boot/vmlinuz-4.4.0-62-generic
Found initrd image: /boot/initrd.img-4.4.0-62-generic
done

root@ubuntu:~# df -m /
Filesystem 1M-blocks Used Available Use% Mounted on
/dev/vda3 1777 1510 154 91% /

root@ubuntu:~# resize2fs /dev/vda3
resize2fs 1.42.13 (17-May-2015)
Filesystem at /dev/vda3 is mounted on /; on-line resizing required
old_desc_blocks = 1, new_desc_blocks = 131
The filesystem on /dev/vda3 is now 548404992 (4k) blocks long.

root@ubuntu:~# df -m /
Filesystem 1M-blocks Used Available Use% Mounted on
/dev/vda3 2013606 1507 1926382 1% /

root@ubuntu:~# /etc/kernel/postinst.d/zz-update-grub 4.4.0-64-generic /boot/vmlinuz-4.4.0-64-generic
Generating grub configuration file ...
grub-probe: error: unknown filesystem.

[Elias Abacioglu (raboo)]

verbose grub-probe

# grub-probe -d /dev/vda -vvvv
grub-probe: info: cannot open `/boot/grub/device.map': No such file or directory.
grub-probe: info: /dev/vda is not present.
grub-probe: info: Looking for /dev/vda.
grub-probe: info: /dev/vda is a parent of /dev/vda.
grub-probe: info: /dev/vda is present.
grub-probe: info: Looking for /dev/vda.
grub-probe: info: /dev/vda is a parent of /dev/vda.
grub-probe: info: /dev/vda is present.
grub-probe: info: Looking for /dev/vda.
grub-probe: info: /dev/vda is a parent of /dev/vda.
grub-probe: info: opening hostdisk//dev/vda.
grub-core/kern/disk.c:196: Opening `hostdisk//dev/vda'...
grub-probe: info: drive = 0.
grub-probe: info: the size of hostdisk//dev/vda is 4404019200.
grub-core/kern/fs.c:56: Detecting zfs...
grub-core/osdep/hostdisk.c:415: opening the device `/dev/vda' in open_device()
grub-core/fs/zfs/zfs.c:1192: label ok 0
grub-core/osdep/hostdisk.c:394: reusing open device `/dev/vda'
grub-core/osdep/hostdisk.c:394: reusing open device `/dev/vda'
grub-core/osdep/hostdisk.c:394: reusing open device `/dev/vda'
grub-core/osdep/hostdisk.c:394: reusing open device `/dev/vda'
grub-core/fs/zfs/zfs.c:1192: label ok 1
grub-core/osdep/hostdisk.c:394: reusing open device `/dev/vda'
grub-core/osdep/hostdisk.c:394: reusing open device `/dev/vda'
grub-core/osdep/hostdisk.c:394: reusing open device `/dev/vda'
grub-core/fs/zfs/zfs.c:1192: label ok 2
grub-core/osdep/hostdisk.c:394: reusing open device `/dev/vda'
grub-core/osdep/hostdisk.c:394: reusing open device `/dev/vda'
grub-core/osdep/hostdisk.c:394: reusing open device `/dev/vda'
grub-core/fs/zfs/zfs.c:1192: label ok 3
grub-core/osdep/hostdisk.c:394: reusing open device `/dev/vda'
grub-core/osdep/hostdisk.c:394: reusing open device `/dev/vda'
grub-core/kern/fs.c:78: zfs detection failed.
grub-core/kern/fs.c:56: Detecting xfs...
grub-core/fs/xfs.c:887: Reading sb
grub-core/fs/xfs.c:243: Validating superblock
grub-core/kern/fs.c:78: xfs detection failed.
grub-core/kern/fs.c:56: Detecting ufs2...
grub-core/kern/fs.c:78: ufs2 detection failed.
grub-core/kern/fs.c:56: Detecting ufs1_be...
grub-core/kern/fs.c:78: ufs1_be detection failed.
grub-core/kern/fs.c:56: Detecting ufs1...
grub-core/kern/fs.c:78: ufs1 detection failed.
grub-core/kern/fs.c:56: Detecting udf...
grub-core/osdep/hostdisk.c:394: reusing open device `/dev/vda'
grub-core/osdep/hostdisk.c:394: reusing open device `/dev/vda'
grub-core/osdep/hostdisk.c:394: reusing open device `/dev/vda'
grub-core/kern/fs.c:78: udf detection failed.
grub-core/kern/fs.c:56: Detecting tarfs...
grub-core/kern/fs.c:78: tarfs detection failed.
grub-core/kern/fs.c:56: Detecting squash4...
grub-core/kern/fs.c:78: squash4 detection failed.
grub-core/kern/fs.c:56: Detecting sfs...
grub-core/kern/fs.c:78: sfs detection failed.
grub-core/kern/fs.c:56: Detecting romfs...
grub-core/kern/fs.c:78: romfs detection failed.
grub-core/kern/fs.c:56: Detecting reiserfs...
grub-core/kern/fs.c:78: reiserfs detection failed.
grub-core/kern/fs.c:56: Detecting procfs...
grub-core/kern/fs.c:78: procfs detection failed.
grub-core/kern/fs.c:56: Detecting odc...
grub-core/kern/fs.c:78: odc detection failed.
grub-core/kern/fs.c:56: Detecting n...

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Jared Baker (shubjero)]

Possibly related bugs:
https://bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/1812411
https://bugs.launchpad.net/cloud-utils/+bug/1762748

We run an OpenStack cloud and provide very large instances to our users and noticed that there was possibly a breaking change made in 1762748 which resulted in my new bug submission 1812411.

I'd be happy to help test this issue as it is easily reproducible in my environment.

Thank you