Cannot create lvm upon IMSM raid array

[Mariusz Tkaczyk]

The issue has been observed on 2.3.7 (Ubuntu 20.04).
Reported to lvm team:
https://bugzilla.redhat.com/show_bug.cgi?id=1855251

Steps to Reproduce:
1. Create IMSM raid array:
#mdadm -CR imsm -e imsm -n2 /dev/nvme[01]n1
#mdadm -CR vol -l1 -n2 /dev/nvme[01]n1 -z 5G

2. Create lvm volume on raid:
# pvcreate -ff -y /dev/md/vol
# vgcreate group0 /dev/md/vol
# lvcreate -Z y -y -l +100%FREE group0 -n lvm0

Actual results:
Vg creation fails.

Expected results:
LVM should be able to determine the best drive and ignore duplicates.

Additional info:
IMSM metadata is written at the end of the drive. The first drive sector belongs to the raid volume and other metadata saved there (like lvm) can be recognized directly on raid members.

The following patches should fix the issue (not verified yet):
https://sourceware.org/git/?p=lvm2.git;a=commit;h=23774f997ea077f2cbe8a32bd8bccdd7f4560cca
https://sourceware.org/git/?p=lvm2.git;a=commit;h=00c9a788cc617e5e40746dee2e17287d61ee5c81

[Jeff Lane  (bladernr)]

Can this please be targeted for 21.10?

[Jeff Lane  (bladernr)]

Mariusz,

> The following patches should fix the issue (not verified yet):
> https://sourceware.org/git/?p=lvm2.git;a=commit;h=23774f997ea077f2cbe8a32bd8bccdd7f4560cca
> https://sourceware.org/git/?p=lvm2.git;a=commit;h=00c9a788cc617e5e40746dee2e17287d61ee5c81

Were those patches verified to fix this in LVM2?

And is there an upstream release version that contains them?

[Graham Inggs (ginggs)]

Both of those patches are present in 2.03.11 which was available in 21.04 and backported to 20.04 (see LP: #1929432).

[Jeff Lane  (bladernr)]

Please verify this is no longer an issue in Focal or Hirsute based on Graham's comment #3 above.

[Mateusz Grzonka (mgrzonka)]

Jeff,
we verified it is no longer an issue on Focal backports.

[Launchpad Janitor (janitor)]

[Expired for lvm2 (Ubuntu) because there has been no activity for 60 days.]

[Launchpad Janitor (janitor)]

[Expired for lvm2 (Ubuntu Focal) because there has been no activity for 60 days.]

[Launchpad Janitor (janitor)]

[Expired for lvm2 (Ubuntu Hirsute) because there has been no activity for 60 days.]