Re: [Xen-devel] dom0 hangs in xen 4.0.1-rc3-pre

["Pasi Kärkkäinen" <pasik@iki.fi>]

On Fri, Sep 24, 2010 at 12:22:21AM -0400, Jia Rao wrote:
>    Hi all,
>    I saw reproducible hangs in dom0 when the system is under heavy load.
>    Testbed settings:
>    four dom0s share a nfs server for domU images. a total number of 24 domUs
>    (6 domUs on each dom0). When the system under heavy load, busy processing
>    e-commerce requests, one or two of the dom0s hanged. no input can be
>    accepted and reboot is necessary.
>    Anyone had the same experience? The causes I can come up are following:
>    1. nfs is not configured properly. But before I upgraded to xen 4, xen 3
>    worked pretty well.
>    2. the domU's are using tap2 disk. Any similar problem in testing tap2?
>    3. Or the problem is from the new pvops kernel ? All the domU are cpu
>    intensive and not generating a lot of IOs.
>    Unfortunately, dom0's dmesg and xm log recorded nothing about the hangs.
>    FYI:
>    Xen: 4.0.1-rc3-pre
>    dom0: centos 2.6.32.1 pvops 8G, 8 cores
>    domU: 2.6.18.8 PV kernel 1G, 4 VCPU
>    NFS server: 8G, 8 cores, 4-disk RAID 5 nfs version 3 over TCP, rw size 4K
>    Interconnect: Gigabyte Ethernet.
>    Thanks a lot !

Well first of all test with Xen 4.0.1 final, does that help? If not, try
Xen 4.0.2-rc1-pre, which has some additional IRQ related fixes.

-- Pasi