I've recently upgraded a Centos 5.3 machine to Centos 5.5. The hardware isn't HVM capabile so I'm only running para-virt guests.

Using a vanilla i386 kernel boots without, but the newer kernel-xen locks up the Dom0 after a couple of minute. I'm only booting into single user mode for these tests so no VMs are active.

kernel-xen-2.6.18-128.1.10.el5 - no issues
kernel-xen-2.6.18-194.17.4.el5 - lock up
kernel-2.6.18-194.17.4.el5 - no issues

For the moment I've switched back to the older Xen kernel, athough I'm still running the newer Xen Hypervisor.

My current Xen packages are

xen-3.0.3-105.el5_5.5
kernel-xen-2.6.18-194.17.4.el5
kernel-xen-2.6.18-128.1.10.el5
kmod-xfs-xen-0.4-2
xen-libs-3.0.3-105.el5_5.5
kernel-xen-devel-2.6.18-194.17.4.el5
kernel-xen-devel-2.6.18-128.1.10.el5
xen-devel-3.0.3-105.el5_5.5

Prior to the upgrade I had the following installed under Centos 5.3

kernel-xen-devel-2.6.18-128.1.6.el5
kernel-xen-2.6.18-128.1.10.el5
xen-libs-3.0.3-80.el5_3.2
xen-devel-3.0.3-80.el5_3.2
kmod-xfs-xen-0.4-2
kernel-xen-2.6.18-128.1.6.el5
kernel-xen-devel-2.6.18-128.1.10.el5
xen-3.0.3-80.el5_3.2

Booting Dom0 with kernel-xen-2.6.18-128.1.10.el5 everything appears to work normally and all of my Guests are up and running.

If I boot with kernel-xen-2.6.18-194.17.4.el5 the boot normally gets to around udev and the system locks up. On a couple of occasions it did mange to boot but reported some files were corrupted. I'm worried that there is an issue running this kernel where the root file system is LVM on top of Raid 1.

Anyone on this list have tips on diagnosing the issue, or come across a similar problem themselves.

Steve