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


[Xen-devel] Re: VM disk I/O limit patch

To: xen-devel@xxxxxxxxxxxxxxxxxxx
Subject: [Xen-devel] Re: VM disk I/O limit patch
From: Shaun Reitan <mailinglists@xxxxxxxxxxxxxxxx>
Date: Thu, 23 Jun 2011 13:45:36 -0700
Cc: xen-users@xxxxxxxxxxxxxxxxxxx
Delivery-date: Thu, 23 Jun 2011 13:46:48 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <20110621162935.F4A1.3A8D29D5@xxxxxxxxxx>
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>
Organization: Network Data Center Host, Inc.
References: <20110621162935.F4A1.3A8D29D5@xxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv: Gecko/20110414 Thunderbird/3.1.10
Does this match only limit throughput or can it also limit the guest by disk IOPS? christopher aker had a patch way back for UML that did disk based qos. What i really liked about that patch was that it allowed for bursting by using a bucket. If i remember correctly you specified that a guest's bucket could hold say 4000 tokens, and the bucket would be filled with 10 tokens a second. Each IO took one token from the bucket. When the bucket was empty IO was paused and processed as the bucket was filled. This allowed a guest to burst for a short period of time until that bucket was empty and then it would slowely be filled back up.

Also what was nice is that the guest had a /proc/ entry that told the customer how many tokens they currently had in their bucket.

I would like to see somthing like this in Xen, I've even thought about posting to the devel forums seeing if somebody wanted to write one for $$$


Xen-devel mailing list