Re: [Xen-users] XM sched-credit

[Paul Piscuc <paul.piscuc@xxxxxxxxxx>]

Yes, this might be a solution. The problem is that on the Dom0 I have no 
application running, except for the firewall, and some nagios plugins, 
that are interrogated by the nagios server. When one guest requires a 
lot of CPU, the nagios server sends an alert that the Dom0 is not 
responding, although is has no load or other issues. This happens almost 
once a week, and the guest OS is used for a database server.
 What would be a better solution ... to pin a cpu for dom0, to change 
the weight for dom0, or to continue using the same sched-credit, and 
tune the nagios server to wait for Dom0 longer?
Thx in advance.
> yes. seems you allocated all cpu ressources away from dom0.
> can you try pinning the vm to one cpu and dom0 to another?
>
> Florian
>
> 2011/1/14 Paul Piscuc<paul.piscuc@xxxxxxxxxx>:
> > Hi,
> >
> > I have modified the sched-credit for one virtual machine, using xm
> > sched-credit -d 0 -w 60000, and the next day Nagios reported some problems
> > on Dom0. Two plugins, that are checking the firewall and smartctl reported
> > "socket timeout after 10 seconds". When I issued the two scripts, one of
> > them took 5 seconds to run, and the other one a few minutes. Here is the
> > first command that took 5 seconds:
> >
> > /sbin/iptables-save|grep -v '^\*' |grep -v '^#' |grep -v '^COMMIT'|grep -v
> > '^:'|wc -l
> >
> > When straced, it pauses for a long time in wait4(). When issued several
> > times, it waits a long time on the third or forth grep. The second one does
> > the same in read(). The load on the dom0 is 0.02, ulimit is ok,and there is
> > no waiting time for the cpu. Also, the virtual machines are running
> > smoothly, without high IO, memory or CPU.
> >
> > Could the problem be generated by the scheduler, that allocated a small
> > weight for the dom0?
> >
> > Thx in advance,
> >
> > Paul PISCUC
> >
> > _______________________________________________
> > Xen-users mailing list
> > Xen-users@xxxxxxxxxxxxxxxxxxx
> > http://lists.xensource.com/xen-users

--
Best regards,
Paul PISCUC
System Administrator - Appnor MSP S.A.
US: (+1) 650 336 57 50
RO: (+4) 021 569 46 56
http://www.appnor.com


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