WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-users

Re: [Xen-users] XM sched-credit

To: Florian Heigl <florian.heigl@xxxxxxxxx>
Subject: Re: [Xen-users] XM sched-credit
From: Paul Piscuc <paul.piscuc@xxxxxxxxxx>
Date: Wed, 19 Jan 2011 14:23:10 +0200
Cc: xen-users@xxxxxxxxxxxxxxxxxxx
Delivery-date: Wed, 19 Jan 2011 04:24:37 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <AANLkTi=ahezUKqecchdSnFXiuOtrWCvLS6gMFByZPe1Y@xxxxxxxxxxxxxx>
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
References: <4D3014A7.6010202@xxxxxxxxxx> <AANLkTi=ahezUKqecchdSnFXiuOtrWCvLS6gMFByZPe1Y@xxxxxxxxxxxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.14pre) Gecko/20110118 Lightning/1.0b2 Shredder/3.1.8pre
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


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

<Prev in Thread] Current Thread [Next in Thread>