Comment 0 for bug 1475941

I've just installed Kubuntu 15.10 and was able to boot into it once and update the kernel. Since then, everytime I try to boot into it I get the following error message:

Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

There might be other error messages before but I cannot see them as they pass too fast, and the only messages I see are those shown in the attached picture.

After some trial and error, I've discovered that this bug occurs when booting with the quiet option. When I remove it, the kernel boots fine most of the time (not everytime, but it's a definite improvement).

What's happening and how do I prevent it?

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: linux-image-3.19.0-22-generic 3.19.0-22.22
ProcVersionSignature: Ubuntu 3.19.0-22.22-generic 3.19.8-ckt1
Uname: Linux 3.19.0-22-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.17.2-0ubuntu1.1
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: fibonacci 1816 F.... pulseaudio
 /dev/snd/pcmC0D0p: fibonacci 1816 F...m pulseaudio
 /dev/snd/controlC0: fibonacci 1816 F.... pulseaudio
CurrentDesktop: KDE
Date: Sat Jul 18 20:28:31 2015
EcryptfsInUse: Yes
HibernationDevice: RESUME=UUID=7e89a62d-4e77-40fc-89ba-42c3b1e76fc0
InstallationDate: Installed on 2015-07-13 (5 days ago)
InstallationMedia: Kubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
IwConfig:
 eth0 no wireless extensions.

 lo no wireless extensions.
ProcFB:

ProcKernelCmdLine: BOOT_IMAGE=/@/boot/vmlinuz-3.19.0-22-generic root=UUID=0e051a2e-be67-40a6-8d32-29d4de69aca1 ro rootflags=subvol=@ splash
RelatedPackageVersions:
 linux-restricted-modules-3.19.0-22-generic N/A
 linux-backports-modules-3.19.0-22-generic N/A
 linux-firmware 1.143.1
RfKill:

SourcePackage: linux
UdevLog: Error: [Errno 2] File o directory non esistente: '/var/log/udev'
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 12/04/2012
dmi.bios.vendor: Intel Corp.
dmi.bios.version: BLH6710H.86A.0160.2012.1204.1156
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: DH67BL
dmi.board.vendor: Intel Corporation
dmi.board.version: AAG10189-206
dmi.chassis.type: 3
dmi.modalias: dmi:bvnIntelCorp.:bvrBLH6710H.86A.0160.2012.1204.1156:bd12/04/2012:svn:pn:pvr:rvnIntelCorporation:rnDH67BL:rvrAAG10189-206:cvn:ct3:cvr: