[Bug 647128] [NEW] Maverick Beta Kernel Panic - "VFS: Unable to mount root fs on unknown-block(0, 0)"

[cactaur]

Public bug reported:

Background:
The hardware I am installing on is a Sony VAIO PCG-FRV26. It previously had Ubuntu 10.04 running on it without any problems. The previous partitioning scheme was
/dev/sda2 | /boot | 2 GB  | ext2
/dev/sda3 | /     | 36 GB | ext4
/dev/sda1 | swap  | 2 GB  | swap
In the spirit of testing, I decided to try Maverick Beta.

Steps to Reproduce:
1. Download and burn Ubuntu Maverick Beta. Do the checksum and CD Integrity checks to make sure the disk isn't corrupted.
[These steps may or may not be relevant]
2. Boot from the CD, and when prompted, use "Try Ubuntu"
3. Set up a wireless connection to the internet.
4. Once the connection is established, double click "Install Ubuntu 10.10" to begin the installation procedure.
5. Select the default values until reaching "Partitioning"
[Probably where something odd happens]
6. Choose a custom partitioning scheme.
7. Edit /dev/sda2, set it as an ext2 /boot partition. Format it. 
8. Edit /dev/sda3, set it as an ext4 / partition. Format it.
9. Click next and choose the defaults for the rest of the installation.
10. Once the installation finishes, restart the computer and remove the CD.
11. When the GRUB bootloader comes up, select the newly installed Ubuntu 10.10.

What should happen:
Since this is a fresh install of Ubuntu, there shouldn't be any problems booting it after the install. After all, there hasn't been an opportunity to screw around with anything.

What happens:
Right after selecting Ubuntu from the GRUB menu, a kernel panic appears and the Caps/Scroll lock lights start flashing. The computer does not do anything after that. When booting in recovery mode, there is more verbose output. Here's the output that results from that:

[0.761431] VFS: Cannot open root device "UUID=3f45a729-2066-4d4f-ae80-3cb2a7c6c4f7" or unknown-block(0,0)
[0.761491] Please append a correct "root=" boot option; here are the available partitions:
[0.761562] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
[0.761662] Pid: 1, comm: swapper Not tainted 2.6.35-19-generic #28-Ubuntu
[0.761671] Call Trace:
[0.761730]  [<c05c572a>] ? printk+0x2d/0x33
[0.761780]  [<c05c5685>] panic+0x5a/0xd2
[0.761832]  [<c0817d8d>] mount_block_root+0x1d3/0x26c
[0.761886]  [<c02247bc>] ? sys_mknod+0x2c/0x30
[0.761935]  [<c0817e7f>] mount_root+0x59/0x5f
[0.761985]  [<c0817fd3>] prepare_namespace+0x14e/0x192
[0.762037]  [<c0217435>] ? sys_access+0x25/0x30
[0.762086]  [<c0817467>] kernel_init+0x18e/0x19d
[0.762134]  [<c08172d9>] ? kernel_init+0x0/0x19d
[0.762185]  [<c010363e>] kernel_thread_helper+0x6/0x10

Other information:
The first time I tried installing 10.10, I selected btrfs as the root partition filesystem to try it out. I got a similar error message, except with "UUID=..." replaced with "root=/dev/sda3". So it looks like the underlying problem is still the same. I figured that btrfs was a beta filesystem and that might be causing problems, so I installed again using ext4 as the root filesystem, and got the error output above.

I also haven't been able to find any similar reports of this so my
system might somehow be an exception situation. But I can't imagine why,
and someone new to Ubuntu might not like being greeted with a kernel
panic on their first boot. So it would be really nice to figure out what
the cause of this might be. Thanks!

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New

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Maverick Beta Kernel Panic - "VFS: Unable to mount root fs on unknown-block(0,0)"
https://bugs.launchpad.net/bugs/647128
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