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] How to Allocate Disk Bandwidth among VMs?

To: tom-xen@xxxxxxxxxxx
Subject: Re: [Xen-devel] How to Allocate Disk Bandwidth among VMs?
From: Ryo Tsuruta <ryov@xxxxxxxxxxxxx>
Date: Tue, 16 Jun 2009 10:45:38 +0900 (JST)
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Mon, 15 Jun 2009 18:46:10 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <23993255.post@xxxxxxxxxxxxxxx>
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: <23993255.post@xxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Hi Tom,

# I'm sorry, I sent an empty e-mail a while ago.

>       I want to do disk I/O rate control over VMs. Therefore, I want to
> allocate different disk I/O bandwidth for different Xen VMs on my host
> machine. All domainUs use file-backed VBDs stored in domain0's file system.
>       Do you have any idea to do that? Hopefully it can be done by modifying
> Xend in domain0.

You can use dm-ioband for this purpose. dm-ioband is an I/O bandwidth
controller implemented as a device-mapper driver and can control
bandwidth on per partition, per user, per process basis.

In this case, install dm-ioband to the host OS, create a
dm-ioband device on the disk which stores domainU's VBD files,
and then assign bandwidth(determined proportional to the weight of
each disk) to each virtual machine.

There is an example configuration available at:
"Example #5: Bandwidth control for Xen blktap devices"

Please see the following URL for more information, kernel patch files
and binary packages for RHEL5 and CentOS5 are availble.

Please feel free to ask me if you have any questions.

Ryo Tsuruta

Xen-devel mailing list