System couldn't boot from degraded raid 1

[loa_rus]

Situation: i created software raid 1 configuration. Boot, swap and root were on different partitions. After that i tried to emulate harddrive problem. For this testcase i used virtualbox machine. I removed one of harddrive containers from virtual machine and tried to boot.

What expected: system boots normal.

What happened: First time after deletion system boots normal, but second time it drops into initramfs. I see that md devices exists in system and i can mount them. And array was marked as degraded. When i return disk back system loads normal, but raid is checked as degraded and i need to add partitions to raid again. But if i don't do it system drops to initramfs again. So looks like system loads with degraded raid only if hardware configuration was changed. Here few screenshots.

Screenshot when system stops booting:
https://dl.dropboxusercontent.com/u/25725476/screenshot-2014.07.13-19%3A17%3A20.png

cat /proc/mdstat:
https://dl.dropboxusercontent.com/u/25725476/screenshot-2014.07.13-19%3A18%3A23.png

mdadm -D /dev/md0:
https://dl.dropboxusercontent.com/u/25725476/screenshot-2014.07.13-19%3A19%3A56.png

cat /etc/fstab:
https://dl.dropboxusercontent.com/u/25725476/screenshot-2014.07.13-19%3A22%3A18.png

lsb_release -rd:
https://dl.dropboxusercontent.com/u/25725476/screenshot-2014.07.13-19%3A37%3A09.png

apt-cache policy mdadm:
https://dl.dropboxusercontent.com/u/25725476/screenshot-2014.07.13-19%3A38%3A07.png

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: mdadm (not installed)
ProcVersionSignature: Ubuntu 3.13.0-29.53-generic 3.13.11.2
Uname: Linux 3.13.0-29-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.14.1-0ubuntu3.2
Architecture: amd64
CurrentDesktop: Unity
Date: Sun Jul 13 19:02:56 2014
InstallationDate: Installed on 2014-06-11 (32 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
SourcePackage: mdadm
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

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

[Michael Krelin (hacker-klever)]

Interestingly enough I could mount root in the (initramfs) shell, maybe it needs more time?

[loa_rus (knight13)]

I can't confirm this bug on real hardware. First i tried to check my future configuration on virtualbox machine. But when i recieved real hardware system worked as expected: when i removed one harddrive system works as usual and there no any problems with degraded mark. After I added drive again i manually added partitions to raid and started rebuild. Maybe this bug only affect virtualbox?

[Michael Krelin (hacker-klever)]

Not in my case. It was real hardware. And I could only boot it after plugging the old drive (even though it wasn't in its best condition and needed to be replaced).

[Martin Hofbauer (mhansi12)]

See my Bug report + workaround there a few minutes ago:
( need to close it ... )

https://bugs.launchpad.net/ubuntu/+bug/1367666

I definitly can confirm this problem, in a VMware workstation and also with real Hardware.

For the degraded MD device you need to boot a second time !!

As described in my bug report problem can also be replicated easly by installing Ubuntu 14.04 on only 1 disk of a RAID1 device

Workaound:

echo "sleep 2" > /etc/initramfs/scripts/local-premount/delay.sh ; chmod +x delay.sh ; update-initramfs -u

( can also be done from the initramfs prompt by mounting the root device + chroot /root )

[loa_rus (knight13)]

Can't get why system don't boot only on second attemp?

[Michael Krelin (hacker-klever)]

It didn't boot on the second attempt for me. Neither on the third. I do believe the workaround above would have helped, but I can't afford taking that system offline now…

[loa_rus (knight13)]

I mean why it boots once, but it does not boot on second attempt. What changed?

[Michael Krelin (hacker-klever)]

Ah, for me it didn't boot once, but since there's timing involved, it could've involved some random amount of luck.

[Michael Krelin (hacker-klever)]

And meanwhile I can confirm putting delay into premount helps.