Partitions on dmriad managed array are not mounted, system cannot boot

[Evgeny Grin]

Starting from jammy (22.04LTS) system failed to add any partitions from dmraid-managed array (Intel Software RAID). The array itself is mounted correctly (both as /dev/dm-0 and /dev/mapper/isw_xxxx), but no partitions are visible (no device like /dev/mapper/isw_xxxx1, /dev/mapper/isw_xxxx2).

It was reported many times on various sites, for example:
https://askubuntu.com/questions/1443274/boot-fails-after-upgrading-from-20-04-to-22-04-on-dmraid-device-no-partitons
https://askubuntu.com/questions/1405817/system-boots-to-initramfs-after-upgrade-from-21-10-to-22-04
https://askubuntu.com/questions/1448141/installation-problems-ubuntu-22-10-on-acer-aspire-3410-1tb-4gb-ram
https://askubuntu.com/questions/1420457/not-booting-from-raid-after-upgrade-from-21-10-to-22-04

If kpartx or partprobe are used on mounted raid device then partitions are added, however the next reboot requires manual actions again.

I was able to trace the problem down to the root cause.

The dmraid package provides udev 97-dmraid.rules file.
This file has lines

ENV{DM_STATE}=="ACTIVE", ENV{DM_UUID}=="DMRAID-*", \
 RUN+="/sbin/kpartx -a /dev/$kernel"

The used environment variable DM_STATE was set by /usr/lib/udev/dmsetup_env (from multipath-tools package) and DM_UUID is set by both dmsetup_env and 55-dm.rules (from dmsetup package).

However, Debian removed dmsetup_env starting from version 0.8.8-1 (dated Jan 2022) of multipath-tools with wrong comment that additional variables are not used anywhere.
See https://metadata.ftp-master.debian.org/changelogs/main/m/multipath-tools/multipath-tools_0.9.4-7_changelog and https://salsa.debian.org/linux-blocks-team/multipath-tools/-/commit/4ab9ce259ffa75ed3e2d145b3f2effc22af7b4c6

As the result DM_STATE is not set anywhere and kpartx from 97-dmraid.rules is not executed anymore.

The possible fixes are:
* restore dmsetup_env (the file could be reduced to set only DM_STATE variable)
* replace second rule in 97-dmraid.rules with
ENV{DM_ACTIVATION}=="1", ENV{DM_UUID}=="DMRAID-*", \
 RUN+="/sbin/kpartx -a /dev/$kernel"

The fix should be used for jammy (22.04LTS), lunar (23.04), mantic (23.10) and noble.

Sidenote: mdadm cannot correctly detect the Intel Software RAID used on my computer.

[Evgeny Grin (k2k-p)]

The problem can be easily reproduced in VM.
Just add two disk devices and create ISW raid on them with dmraid.

I used the next command to create test array:

dmraid -f isw -C HDD_SWRAID --type 0 --disk /dev/sda,/dev/sdb

Then create any partition on the array and reboot. The block devices will be "visible" for the system, but partitions are not.

[Ubuntu Foundations Team Bug Bot (crichton)]

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[pasaporte (josedky73)]

Thank you for the fix, I couldn't understand why the raid would be detected on first install, and then if I assigned a partition to be mounted on load the system would just time out, I really appreciate it. Kudos to you.

[Launchpad Janitor (janitor)]

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