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/
Home Products Support Community News


Re: [Xen-devel] [RFC][PATCH] Increase hotplug timeout

To: Ian Jackson <Ian.Jackson@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [RFC][PATCH] Increase hotplug timeout
From: "Daniel P. Berrange" <berrange@xxxxxxxxxx>
Date: Thu, 16 Apr 2009 11:59:07 +0100
Cc: Jiri Denemark <jdenemar@xxxxxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Thu, 16 Apr 2009 03:59:42 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <18919.3354.673265.359229@xxxxxxxxxxxxxxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <20090415144142.GA9633@xxxxxxxxxx> <18919.3354.673265.359229@xxxxxxxxxxxxxxxxxxxxxxxx>
Reply-to: "Daniel P. Berrange" <berrange@xxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.4.1i
On Thu, Apr 16, 2009 at 11:48:58AM +0100, Ian Jackson wrote:
> Jiri Denemark writes ("[Xen-devel] [RFC][PATCH] Increase hotplug timeout"):
> > When a process in dom0 is writing huge amount of data to a disk in
> > parallel to creating new domain, it may take quite a lot of time
> > until all hotplug scripts finish. For example, on my system it takes
> > almost 5 minutes to start all hotplug scripts.
> That's a very long time.  All of that for just one domain ?
> > So it seems 100 seconds is not enough for such scenarios as xend
> > would give up waiting for hotplug scripts too early. What do you
> > think about the attached patch, which increases the timeout to 10
> > minutes? Of course, the dark side of this change is that it would
> > take ages to recognize hotplug scripts are not really working.
> I think very few people have configurations like yours.

It is a problem that gets more common as you add more devices. eg if
you have lots of disks or nics then it becomes much more likely to
occur. Add in a 2nd guest which is doing alot of I/O at the same time
you are trying to start this guest and it gets worse again, because
xenstored I/O performance starts to hurt. Having xenstored on tmpfs 
should make it happen less. Having a fully in memory xenstored without
any need for tmpfs at all, would be even better.

|: Red Hat, Engineering, London   -o-   http://people.redhat.com/berrange/ :|
|: http://libvirt.org  -o-  http://virt-manager.org  -o-  http://ovirt.org :|
|: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :|
|: GnuPG: 7D3B9505  -o-  F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|

Xen-devel mailing list

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