[CentOS] xen domu not starting

Sun Dec 20 11:44:26 UTC 2009
Peter Peltonen <peter.peltonen at gmail.com>

After running out of swap and memory and freezing, a domU called web02
won't start up.

Both dom0 and domU are running CentOS release 5.4. dom0's kernel is
2.6.18-164.el5xen and I'm running the
stock xen from CentOS: xen-3.0.3-94.el5

After issuing 'xen create web02' I see the following in the xen console:

Inode-cache hash table entries: 65536 (order: 6, 262144 bytes)
vmalloc area: ee000000-f4ffe000, maxmem 2d800000
Memory: 1031328k/1056768k available (1478k kernel code, 16784k
reserved, 548k data, 132k init, 311296k highmem)
Checking if this processor honours the WP bit even in supervisor mode... Ok.
Security Scaffold v1.0.0 initialized
SELinux:  Initializing.
selinux_register_security:  Registering secondary module capability
Capability LSM initialized as secondary
Mount-cache hash table entries: 512 (order: 0, 4096 bytes)
CPU: L1 I cache: 32K, L1 D cache: 32K
CPU: L2 cache: 6144K
Enabling fast FPU save and restore... done.
Enabling unmasked SIMD FPU exception support... done.
Checking 'hlt' instruction... OK.
CPU 1 irqstacks, hard=c0344000 soft=c0324000
Brought up 1 CPUs
checking if image is initramfs... it is
Freeing initrd memory: 1232k freed
Grant table initialized
NET: Registered protocol family 16
Initializing CPU#1
Brought up 2 VCPUs

But after that it just hangs. SSH won't respond either. 'xm list' shows:

web02                                     25     1023     2 -b----      0.9

All I see in dom0's xend log is:

Dec 20 13:18:10 kr kernel: device vif25.0 entered promiscuous mode
Dec 20 13:18:10 kr kernel: ADDRCONF(NETDEV_UP): vif25.0: link is not ready
Dec 20 13:18:12 kr kernel: blkback: ring-ref 8, event-channel 9,
protocol 1 (x86_32-abi)
Dec 20 13:18:12 kr kernel: ADDRCONF(NETDEV_CHANGE): vif25.0: link becomes ready
Dec 20 13:18:12 kr kernel: xenbr0: topology change detected, propagating
Dec 20 13:18:12 kr kernel: xenbr0: port 5(vif25.0) entering forwarding state

In dom0's /var/log/messages I see:

Dec 20 13:18:12 kr kernel: blkback: ring-ref 8, event-channel 9,
protocol 1 (x86_32-abi)
Dec 20 13:18:12 kr kernel: ADDRCONF(NETDEV_CHANGE): vif25.0: link becomes ready
Dec 20 13:18:12 kr kernel: xenbr0: topology change detected, propagating
Dec 20 13:18:12 kr kernel: xenbr0: port 5(vif25.0) entering forwarding state

xm dmesg reports nothing unusual except these at the end:

(XEN) mm.c:649:d22 Error getting mfn 3b6 (pfn 55555555) from L1 entry
00000000003b6025 for dom22
(XEN) mm.c:3341:d22 ptwr_emulate: fixing up invalid PAE PTE 00000000003b6025

But I've no idea when those messages have been created.

I've disabled selinux in dom0.

Other domUs are running fine, although I haven't tried rebooting them.

Any ideas what could be wrong with the domU?

Regards,
Peter