Re: [Xen-users] DomUs randomly freezing

[Stephan Seitz <s.seitz@xxxxxxxxxxxx>]

Hi,

I would try to check following:

        - is dom0 able to take the load?
        I found bridging in dom0 with about 30 domU's an intensive task
        which can easily utilize 2 CPU cores. CPU pinning may help.

        - is dom0 min-mem high enough to not run out of memory?

        - are you able to xm console to a frozen domU?
        Just evaluate if only the networking is frozen or if the domUs
        are generally unreachable. What shows xentop ?

        - if this is a networking issue, are you using tcp offload?
        Maybe, you might try to ethtool -K INTERFACE tx off in every
        bridge connected domU. Setting dom0 also wont harm.

        - is the machine able to take the disk i/o ?
        AFAIK hard to measure, but xentop and vmstat should help investigating
        into this.

Cheers,

Stephan


Stefan Kögl schrieb:
> Hi,
>
> I'm using Xen on an up-to-date RedHat server with CentOS in the DomUs.
> Randomly and not reproducible, the DomUs are freezing, causing SSH
> connections to be aborted. Also, the DomUs don't react to pings during
> this times. Locally, I can't find any evidence of this problems. The
> log files don't contain suspicious entries during this times. The
> whole problem lasts one, maybe two minutes, and then everything is
> back to normal.
>
> The host server is also reachable during this period, so network
> problems are not part of the problem.
>
> Can anyone point me on where to search for the source of the problem?
>
> tia,
>
> Stefan
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-users

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Stephan Seitz
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