udev race with kernel causes mountall problems detecting lvm volumes

[Matt Grant]

Binary package hint: udev

On system boot, it looks like udev has a race condition with the detection of lvm file systems. I have seen 1 or 2 kernel messages about udev not being able to pass on notices about /dev/sda4, my LVM partition.

Plymouth is displaying messages about 'not being able to find the disk for /home' and other LVM
volumes I have on my laptop.

This happens not matter which kernel I boot, kernel.org 2.6.33.2 or the current one in lucid.

Versions of udev and mountall:

udev: 151-11
mountall: 2.12

I have a /dev/sda3 root which is a primary partition, and the LVM volume is on /dev/sda4, another primary partition.

This is all on amd64, after a update-manager -d upgrade.

I have done a dpkg --purge --force-depends on udev and mountall, and reinstalled them via apt-get, but the problem still persists.

Another thing to note, I was fortunately only able to break this deadlock as I have a practice of setting the root password away from the random one set by the Ubuntu installer. Most installations of Ubuntu I have seen have a non-usable sulogin, which means on a failure like this, or a fsck failure, the user usually can't recover or triage the situation.

[Scott James Remnant (Canonical) (canonical-scott)]

udev can't race with the kernel ... all udev does is respond to messages *from* the kernel - the lvm system should send change events if the original events were invalid

(there are sporadic reports something has broken in recent kernels wrt this, but reassigning to lvm since that's where the triage is taking place)

[Scott James Remnant (Canonical) (canonical-scott)]

Thanks!

Your comment about udev not being able to deliver the message was a big clue that the buffer size was wrong in mountall