Kernel panic - not syncing: VFS: Unable to mount root fs

[Gil Tygart Sr]

Got kernel panic at boot and could not reach grub using shift. Found Bug #1547559, saw this comment by Jason Straight.

"Stumbled across this today while searching for a fix for a PC running 16.04 that this is happening on. I don't understand why, but editing /etc/default/grub to uncomment the line for graphical terminal fixed it. What that has to do with mounting root I don't know, but that was certainly the fix."

"Uncommenting #GRUB_TERMINAL=console fixed it."

Yes, it does. Not sure if this is related or not so new bug.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.4.0-45-generic 4.4.0-45.66
ProcVersionSignature: Ubuntu 4.4.0-45.66-generic 4.4.21
Uname: Linux 4.4.0-45-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_modeset nvidia
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC2: gilsr 2587 F.... pulseaudio
 /dev/snd/controlC1: gilsr 2587 F.... pulseaudio
 /dev/snd/controlC0: gilsr 2587 F.... pulseaudio
CurrentDesktop: Unity
Date: Sun Oct 23 19:53:47 2016
HibernationDevice: RESUME=UUID=6b783c22-05f6-4b87-8d0b-5f23d003361b
InstallationDate: Installed on 2016-10-08 (15 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
IwConfig:
 lo no wireless extensions.

 eno1 no wireless extensions.
ProcFB:

ProcKernelCmdLine: BOOT_IMAGE=/@/boot/vmlinuz-4.4.0-45-generic root=UUID=b69ab98a-b1e4-4612-a1b2-1cfb9f742265 ro rootflags=subvol=@ quiet splash
RelatedPackageVersions:
 linux-restricted-modules-4.4.0-45-generic N/A
 linux-backports-modules-4.4.0-45-generic N/A
 linux-firmware 1.157.4
RfKill:
 0: hci0: Bluetooth
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 11/01/2012
dmi.bios.vendor: Intel Corp.
dmi.bios.version: BHZ7710H.86A.0094.2012.1101.1115
dmi.board.name: DZ77BH-55K
dmi.board.vendor: Intel Corporation
dmi.board.version: AAG39008-400
dmi.chassis.type: 3
dmi.modalias: dmi:bvnIntelCorp.:bvrBHZ7710H.86A.0094.2012.1101.1115:bd11/01/2012:svn:pn:pvr:rvnIntelCorporation:rnDZ77BH-55K:rvrAAG39008-400:cvn:ct3:cvr:

[Gil Tygart Sr (gtygartsr)]

Only other thing I remember from the kernel panic screen was a mention of Block (0,0).

[Gil Tygart Sr (gtygartsr)]

Also, root on btrfs.

[Brad Figg (brad-figg)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Did this issue start happening after an update/upgrade? Was there a prior kernel version where you were not having this particular problem?

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.9 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.9-rc2

[bogyo (bogyo)]

The same here.

Original install: ubuntu gnome 16.04.
root fs: btrfs
After upgrading to 16.10 all new (4.8) kernels hanging up with this message.
Tried with 4.9.0-rc4, the problem still exists.
Boots correctly with kernel 4.4.0-43

"Uncommenting #GRUB_TERMINAL=console fixed it." - for me it has not solved the problem.

Thank you.

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]