/proc/self/mountinfo:no such file or directory after upgrading from 9.04 to 9.10

I had the same problem, and also couldn't figure out how to solve it. I ended up re-installing from the 9.10 LiveCD and that make the system work again. (Luckily, I have my /home and / partitions separate so I didn't lose any important data.)

I have the same problem on a virtual server which I upgraded from 9.04 to 9.10.
It's running a 2.6.20-xen-r6 kernel and the file mountinfo doesn't exist.

I confirm it using uml (user mode linux) with karmic host and karmic guest.

uname -a
-----------------------------------------------------
Linux divinelaptop 2.6.31-20-server #57-Ubuntu SMP Mon Feb 8 09:59:59 UTC 2010 x86_64 GNU/Linux
-----------------------------------------------------

boot message:
-----------------------------------------------------
[42949373.760000] ReiserFS: ubda: checking transaction log (ubda)
[42949373.760000] ReiserFS: ubda: Using tea hash to sort names
[42949373.760000] VFS: Mounted root (reiserfs filesystem) readonly.
[42949373.760000] line_ioctl: tty0: ioctl KDSIGACCEPT called
mountall:/proc: unable to mount: Device or resource busy
mountall:/proc/self/mountinfo: No such file or directory
mountall: root filesystem isn't mounted
init: mountall main process (637) terminated with status 1
General error mounting filesystems.
A maintenance shell will now be started.
CONTROL-D will terminate this shell and re-try.
-----------------------------------------------------

so I try mountall --debug
-----------------------------------------------------
root@divinelaptop:~# mountall --debug
track_usplash: will not start usplash
parse_filesystems: reading filesystems
parse_filesystems: sysfs (nodev)
parse_filesystems: rootfs (nodev)
parse_filesystems: bdev (nodev)
parse_filesystems: proc (nodev)
parse_filesystems: debugfs (nodev)
parse_filesystems: sockfs (nodev)
parse_filesystems: pipefs (nodev)
parse_filesystems: anon_inodefs (nodev)
parse_filesystems: futexfs (nodev)
parse_filesystems: tmpfs (nodev)
parse_filesystems: inotifyfs (nodev)
parse_filesystems: devpts (nodev)
parse_filesystems: reiserfs
parse_filesystems: ext3
parse_filesystems: ext4dev
parse_filesystems: ext2
parse_filesystems: ramfs (nodev)
parse_filesystems: jfs
parse_filesystems: xfs
parse_filesystems: hostfs (nodev)
parse_filesystems: hppfs (nodev)
parse_filesystems: mqueue (nodev)
new_mount: /: /dev/root rootfs defaults check
new_mount: /proc: - proc nodev,noexec,nosuid
new_mount: /proc/sys/fs/binfmt_misc: - binfmt_misc nodev,noexec,nosuid,optional
new_mount: /sys: - sysfs nodev,noexec,nosuid
new_mount: /sys/fs/fuse/connections: - fusectl optional
new_mount: /sys/kernel/debug: - debugfs optional
new_mount: /sys/kernel/security: - securityfs optional
new_mount: /spu: - spufs gid=spu,optional
new_mount: /dev: - tmpfs mode=0755 hook
new_mount: /dev/pts: - devpts noexec,nosuid,gid=tty,mode=0620
new_mount: /dev/shm: - tmpfs nosuid,nodev
new_mount: /tmp: - - - hook
new_mount: /var/run: - tmpfs mode=0755,nosuid,showthrough hook
new_mount: /var/lock: - tmpfs nodev,noexec,nosuid,showthrough
new_mount: /lib/init/rw: - tmpfs mode=0755,nosuid,optional
parse_fstab: updating mounts
update_mount: /: /dev/ubd0 reiserfs defaults check
update_mount: /proc: proc proc defaults
mount_proc: mounting /proc
mountall:/proc: unable to mount: Device or resource busy
mountall:/proc/self/mountinfo: No such file or directory
mount_policy: /proc/sys/fs/binfmt_misc: dropping unknown filesystem
mount_policy: /sys/fs/fuse/connections: dropping unknown filesystem
mount_policy: /sys/kernel/security: dropping unknown filesystem
mount_policy: /spu: dropping unknown filesystem
mount_policy: / ...

karmic host and hardy guest works correctly.
karmic host and jaunty guest do not work. (same as karmic guest)

associating with update-manager package

Got the same problem.
Using 8.04 Server.
I wasn't doing a full upgrade to 9.1, just some packages. And as a result of dependecies mountall was installed in system.
The only available now kernel is 2.6.24-23-server, so modifing menu.lst to point to 2.6.31 is impossible.
Is there any way I can get my system working back so I could do a correct upgrade to 9.10?

Solved by removing mountall and reinstalling ubuntu-minmal, startup-tasks, system-services, upstart(with recomended packages) from hardy CDROM

Thank you for taking the time to report this bug and helping to make Ubuntu better. We are sorry that we do not always have the capacity to look at all reported bugs in a timely manner. There have been many changes in Ubuntu since that time you reported the bug and your problem may have been fixed with some of the updates. It would help us a lot if you could test it on a currently supported Ubuntu version. When you test it and it is still an issue, kindly upload the updated logs by running apport-collect 477053 and any other logs that are relevant for this particular issue.

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