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I Seem to be having an issue with a Xen guest not booting after a yum update.

DomU Configuration:

#kernel     = '/boot/solus-vmlinuz'
#ramdisk    = '/boot/solus-initrd.img'
bootloader = '/usr/bin/pygrub'
extra      = ''
memory     = 128
hostname   = ''
cpu_weight = 256
name       = 'vm111'
vif        = ['ip=, vifname=vifvm111.0, mac=00:16:3e:05:8a:8a, rate=1280KB/s']
vnc        = 0
vcpus      = 1
vncviewer  = 0
serial     = 'pty'
disk       = ['phy:/dev/vg0/vm111_img,xvda1,w', 'phy:/dev/vg0/vm111_swap,xvda2,w']
#root       = '/dev/xvda1 ro'

The guest OS, CentOS 6.4 x86_64 boots fine with kernel 2.6.32-358.0.1.el6.x86_64.

However after;

#yum update

Dependencies Resolved

 Package Arch Version Repository
 kernel x86_64 2.6.32-358.2.1.el6 updates 26 M
 initscripts x86_64 9.03.38-1.el6.centos.1 updates 937 k
 kernel-firmware noarch 2.6.32-358.2.1.el6 updates 11 M
 krb5-libs x86_64 1.10.3-10.el6_4.1 updates 760 k
 selinux-policy noarch 3.7.19-195.el6_4.3 updates 1.8 M
 selinux-policy-targeted noarch 3.7.19-195.el6_4.3 updates 2.8 M
 tzdata noarch 2013b-1.el6 updates 457 k

Transaction Summary
Install 1 Package(s)
Upgrade 6 Package(s)

Total download size: 44 M
#Is this ok [y/N]:y

# cat /boot/grub/grub.conf
title CentOS (2.6.32-358.2.1.el6.x86_64)
  root (hd0,0)
  kernel /boot/vmlinuz-2.6.32-358.2.1.el6.x86_64 console=hvc0 xencons=tty0 root=/dev/xvda1 ro crashkernel=auto
  initrd /boot/initramfs-2.6.32-358.2.1.el6.x86_64.img
title vmlinuz-2.6.32-358.0.1.el6.x86_64
  root (hd0,0)
  kernel /boot/vmlinuz-2.6.32-358.0.1.el6.x86_64 console=hvc0 xencons=tty0 root=/dev/xvda1 ro
  initrd /boot/initramfs-2.6.32-358.0.1.el6.x86_64.img

The Xen guest fails to reboot. The following is a (partial) serial console output of the boot process:

dracut: dracut-004-303.el6
udev: starting version 147
dracut: Starting plymouth daemon
dracut Warning: No root device "block:/dev/xvda1" found

dracut Warning: Boot has failed. To debug this issue add "rdshell" to the kernel command line.

dracut Warning: Signal caught!

dracut Warning: Boot has failed. To debug this issue add "rdshell" to the kernel command line.
Kernel panic - not syncing: Attempted to kill init!
Pid: 1, comm: init Not tainted 2.6.32-358.2.1.el6.x86_64 0000001
Call Trace:
 [<ffffffff8150d248>] ? panic+0xa7/0x16f
 [<ffffffff81073ae2>] ? do_exit+0x862/0x870
 [<ffffffff81182965>] ? fput+0x25/0x30
 [<ffffffff81073b48>] ? do_group_exit+0x58/0xd0
 [<ffffffff81073bd7>] ? sys_exit_group+0x17/0x20
 [<ffffffff8100b072>] ? system_call_fastpath+0x16/0x1b

Is this an issue with the updated kernel, or do I have my DomU configured incorrectly?

share|improve this question
Have you tried to boot using the old kernel? – user1007727 Mar 27 '13 at 19:48

Probably the cause could be a missing depmod during the kernel upgrade. Boot on your old kernel and try this:

yum upgrade module-init-tools
depmod -ae -F /boot/ 2.6.32-358.2.1.el6
dracut --force '' 2.6.32-358.2.1.el6
share|improve this answer

if your domU doesn't find the root device, try in this way

mkinitrd -f -v --preload xenblk /boot/initramfswithxenblk.img $(uname -r)

in your guest configuration file

kernel = path of your kernel
ramdisk = /boot/initramfswithxenblk.img
share|improve this answer

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