From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Creck Subject: Re: How to Allocate Disk Bandwidth among VMs? Date: Tue, 16 Jun 2009 01:36:54 -0700 (PDT) Message-ID: <24049942.post@talk.nabble.com> References: <23993255.post@talk.nabble.com> <20090616.104538.189700018.ryov@valinux.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090616.104538.189700018.ryov@valinux.co.jp> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Thank you a lot for your reply. I will try dm-ioband for Xen disk I/O QoS ASAP. Actually, I'm also surveying ways of Xen disk I/O QoS. There are two kinds of solution as I see. One is at the frontend/backend driver level. It avoids replying on any specific guest OS. There are two patches for this same purpose. The first is Xen I/O manager. (http://lists.xensource.com/archives/html/xen-devel/2007-07/msg00863.html) The second is a token-based resource limitation in backend driver (http://www.nabble.com/-PATCH-0-2--blkback:-Token-based-QoS-resource-limiting-for-VBD-I-O.-td22808160.html) However, my lastest Xen 3.3.0 doesn't include either. I wonder does Xen 3.3.0 incorporate any disk I/O QoS mechanism inside? The second kind of solution, as the one you suggest, bases on Domain0 OS kernel's scheduling of backend driver's kernel thread, such as dm-ioband and ionice for per-process scheduling. I tried ionice, but got no effect. I don't know why. Is there any other idea or implementation for disk I/O QoS in Xen? Ryo Tsuruta wrote: > > 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" > http://sourceforge.net/apps/trac/ioband/wiki/dm-ioband/man/examples > > Please see the following URL for more information, kernel patch files > and binary packages for RHEL5 and CentOS5 are availble. > http://sourceforge.net/apps/trac/ioband/wiki/dm-ioband > > Please feel free to ask me if you have any questions. > > Thanks, > Ryo Tsuruta > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel > > -- View this message in context: http://www.nabble.com/How-to-Allocate-Disk-Bandwidth-among-VMs--tp23993255p24049942.html Sent from the Xen - Dev mailing list archive at Nabble.com.