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-users] xm save -c

To: "Nick Couchman" <Nick.Couchman@xxxxxxxxx>
Subject: Re: [Xen-users] xm save -c
From: "Mike Sun" <msun@xxxxxxxxxx>
Date: Thu, 13 Nov 2008 20:45:56 -0500
Cc: XEN Mailing List <xen-users@xxxxxxxxxxxxxxxxxxx>, xen-research@xxxxxxxxxxxxxxxxxxx
Delivery-date: Thu, 13 Nov 2008 17:46:34 -0800
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:sender :to:subject:cc:in-reply-to:mime-version:content-type :content-transfer-encoding:content-disposition:references :x-google-sender-auth; bh=5qX4a+rvOnAcfIyMqhH/9kAbBOia58jPVNHIEnB4XO0=; b=s4rFLopaem5V8mcsYusTwtqbA8anKqVHwErrptmAGc6J3i3eamj7IKtohcLcwunNG7 qHZ2UiLxaItxdi/v6uZGyJreOq4RSzXF9xefx1XkpNTYthlCGLGeNqwVu7KlfixxwDC0 nqYrd0dZXJMGVDpzI9wMkbM9zxT3yw3l2/eyM=
Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references:x-google-sender-auth; b=nDTUn65AC8foW0m70EenQblNAA327KN83xMiRMRyz4Fjkdw2yN8E5Bwhy6j8AFr9jn O4Q6Kfpul2EuGdMH/xYSP3g4ROsRiWTWlWS+jiIrjDErl5y7QUCAxs1wyjV+oXaYXggY T37Q9leyghtF76xbKEYVymd7s6nryi/cxn1OY=
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <48DE2BA7.87A6.0099.1@xxxxxxxxx>
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: <48DE2BA7.87A6.0099.1@xxxxxxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
Hi Nick,

> I was wondering if anyone knows of a way to "checkpoint" without pausing the
> domain?  I can't do something like an hourly checkpoint if the domain pauses
> every hour - the users on the domUs would kill me.  Is "seamless
> checkpointing" something that's being developed, something that can be done
> another way, or something I should just give up on now?

I've been working on something for my research that probably addresses
what you're looking for: low latency/downtime checkpointing.  There
are two ways I know this can be done.

You can modify the live-migration mechanism in Xen to save a
checkpoint instead of migrating to another host.  I don't know why
this hasn't been provided in the xm save tool, but it's a pretty
simple hack to get working since the xm migrate and xm save codebase
is basically the same.  If you're interested, I can send patches to
allow you to do that.  Then basically on a checkpoint, pre-copying
would be used to cut the actual time the domU has to be paused.

The other way that I've implemented for my research project is to use
copy-on-write.  I've implemented a prototype and in the middle of
writing paper for publication.  It's not suited for production use,
but I'd be glad to contribute the code if there's interest.


Xen-users mailing list

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