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Re: [Xen-users] Domain 0 reboot when network flow is heavy

Hello Xin.

In our case, the disk I/O load was always in the DomU (via a passthrough block device from Dom0), and was always associated with high network traffic, as our SAN is ethernet attached (AoE, not iSCSI).

We can crash the system through DomU disk I/O and associated network traffic alone. Accessing /proc/slabinfo greatly exacerbated the problem.

P.S. You're missing 'cat' in the script your showed:

!#/bin/sh
while [ 1 ] do
cat /proc/slabinfo >> ./slabinfo.txt
end

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On Jun 27, 2007, at 3:39 AM, Xin Chen wrote:

Thanks Tom,

I did these experiments on domain 0 today:
First, I shutdown the guest systems running on domain 0, in case domain 0 reboots.

1, write a script:
!#/bin/sh
while [ 1 ] do
/proc/slabinfo >> ./slabinfo.txt
end

then keep this script running around 20 mins, until slabinfo.txt about 4gb, domain 0 still running ok.

2, choose a 10gb file called temp, and do scp
#scp temp localhost:/tmp/temp
copying speed: 25mb/s, domain 0 still running ok.

3, again, like yesterday, scp a large file from remote server to domain 0. I did it twice, and domain 0 still running ok.

I am not sure what it tells, I need to test again. Just may give a idea that it only happens when there is a guest running???

xin



Tom Mornini wrote:

This sounds very similar to bugs we've seen with Xen version before 3.1

We believe the problem to be disk I/O related, but in our environment, disk I/O is also network I/O, so it's hard to tell.

We believe this problem to be corrected in 3.1, but we still haven't done enough testing to satisfy ourselves entirely on this.

See this previous thread:

http://lists.xensource.com/archives/html/xen-users/2007-03/ msg00073.html




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