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

[thehhhe]

I'm getting a kernel panic when i try with the standard kernel for Ubuntu 14.04.4 LTS: 3.19.0-26.
It says "Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)"
I also use btrfs on the root partition (this may be relevant).
I attached a photo of the kernel panic screen.

When i boot into an older kernel (3.13.0-77-generic) everything works.
Currently I'm on linux-generic-lts-wily (4.2.0-27-generic), because that one also works.

I made this bug report with the older kernel, so the kernel-version from the automatic debug-information is wrong.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-77-generic 3.13.0-77.121
ProcVersionSignature: Ubuntu 3.13.0-77.121-generic 3.13.11-ckt32
Uname: Linux 3.13.0-77-generic x86_64
NonfreeKernelModules: nvidia zfs zunicode zcommon znvpair zavl
ApportVersion: 2.14.1-0ubuntu3.19
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: david 7048 F.... pulseaudio
 /dev/snd/controlC2: david 7048 F.... pulseaudio
 /dev/snd/controlC0: david 7048 F.... pulseaudio
CurrentDesktop: GNOME
Date: Fri Feb 19 15:49:46 2016
InstallationDate: Installed on 2015-08-25 (177 days ago)
InstallationMedia: Ubuntu-GNOME 14.04.3 LTS "Trusty Tahr" - Beta amd64 (20150805)
IwConfig:
 eth0 no wireless extensions.

 eth1 no wireless extensions.

 lo no wireless extensions.
MachineType: System manufacturer System Product Name
ProcFB:

ProcKernelCmdLine: BOOT_IMAGE=/@/boot/vmlinuz-3.13.0-77-generic root=UUID=aad80ea5-bb9e-42ce-9082-5ba768811185 ro rootflags=subvol=@ quiet splash
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-77-generic N/A
 linux-backports-modules-3.13.0-77-generic N/A
 linux-firmware 1.127.20
RfKill:
 0: hci0: Bluetooth
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 11/09/2012
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1709
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: P8Z77-V DELUXE
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: Rev 1.xx
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1709:bd11/09/2012:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnP8Z77-VDELUXE:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.name: System Product Name
dmi.product.version: System Version
dmi.sys.vendor: System manufacturer

[Brad Figg (brad-figg)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream stable kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.19 stable 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'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-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/v3.19.8-ckt15-vivid/

[thehhhe (thehhhe)]

I tested the v3.19.8-ckt15-vivid kernel and also the 3.19.0-49 kernel. Both of them seemed to boot, but there were graphical glitches and I could not read or do anything.

[Jason Straight (jason-jeetkunedomaster)]

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.

I noticed that I could hold shift and select the same kernel, with the same command line options, under the advanced menu and get the system to boot. Uncommenting #GRUB_TERMINAL=console fixed it.