Xen users - Aug 2011 - random reboots on Debian Squeeze 6.0.2.1 + Xen 4.02 on top of OCFS2 1.4.4-3

This might be related to a posting a couple of days ago on random 
reboots, but the problem arises from a different environment and situation.

We are running a two-node cluster. Both nodes run Debian Squeeze 6.0.2.1 
+ Xen 4.02 on top of OCFS2 1.4.4-3. Kernel is 2.6.32-5-xen-amd64. Both 
nodes store and run vms on the ocfs2 partition, which is accessed from 
the 2 boxes via ISCSI.  We run a network stress test in which the 2 vms 
pass a large file between them. One vm has an nfs share with the file in 
it, and the other vm copies this file (arbitrarily, a large, 4.6 Gb 
debian.iso file) to and from the nfs file share to its own local 
directory. Currently, network configuration giving us no problems--no 
lost packets, collisions, etc.

The vms are lucid instances (ubuntu 10.04) created by the following command:

sudo xen-create-image --hostname lucidxentest --ip 163.1.86.9 --pygrub
+ xen-tools.conf params-- size = 8 Gb, image = full, mem. = 512, swap = 512


The stress proceeds successfully for anywhere from 1 to 12 hours, then 
the system reboots. The file move has been interrupted, the vms crashed, 
with one of the nodes rebooted.

I have noticed occasional reporting of a kernel error (linux/mm/slub.c 
2969!), similar to a Debian bug (#634047). But I find no firm 
correlation, as often kern.log and messages logs do not usually report 
this kernel error.

Some things I have tried:

a basic reinstall of the all the components of the system (squeeze + xen 
+ ocfs2)

a memtest on both nodes. (no problems).

changing the default Debian IO scheduler in combination with ocfs2: cfq, 
deadline, anticipatory, no op.

currently investigating, but have not yet investigated, adjusting: (1) 
halt state set in BIOS; (2) setting of cpufreq=dom0-kernel, frequency 
scaling.


Any suggestions are welcome!

Ben Weaver














_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users