From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Markey Subject: Re: XCP: RFC: compressing VM exports by default Date: Tue, 22 Jun 2010 15:17:39 +0100 Message-ID: References: <81A73678E76EA642801C8F2E4823AD218080C98A1E@LONPMAILBOX01.citrite.net> Reply-To: admin@dmarkey.com Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1947328129==" Return-path: In-Reply-To: <81A73678E76EA642801C8F2E4823AD218080C98A1E@LONPMAILBOX01.citrite.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Dave Scott Cc: "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org --===============1947328129== Content-Type: multipart/alternative; boundary=001485f4277274dcd204899f1523 --001485f4277274dcd204899f1523 Content-Type: text/plain; charset=ISO-8859-1 Hmm could increase Dom0 load during an export. I think its a good idea overall however. On 22 June 2010 15:08, Dave Scott wrote: > Hi, > > In XCP a VM "export" is a serialized VM, including metadata and usually raw > disk blocks. The format is a very simple tar file (really stream) with an > XML file at the front containing version information and metadata. > > Unfortunately VM exports containing raw disk blocks can be very large and > their size makes them difficult to store and distribute over the network. I > propose to turn on compression by default by filtering the exports through > gzip and to auto-detect both compressed and uncompressed exports on import. > > I've written up my proposal on the wiki: > > http://wiki.xensource.com/xenwiki/Compressing_VM_exports > > One implication is that new (compressed) exports will fail to import on > older servers. However (a) there's an easy workaround (gunzip); and (b) I > think being able to import an old (uncompressed) export on a new server is > more important than the other way around. > > Comments appreciated! > > Cheers, > Dave > > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel > --001485f4277274dcd204899f1523 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hmm could increase Dom0 load during an export.

I think i= ts a good idea overall however.

On 22 Jun= e 2010 15:08, Dave Scott <Dave.Scott@eu.citrix.com> wrote:
Hi,

In XCP a VM "export" is a serialized VM, including metadata and u= sually raw disk blocks. The format is a very simple tar file (really stream= ) with an XML file at the front containing version information and metadata= .

Unfortunately VM exports containing raw disk blocks can be very large and t= heir size makes them difficult to store and distribute over the network. I = propose to turn on compression by default by filtering the exports through = gzip and to auto-detect both compressed and uncompressed exports on import.=

I've written up my proposal on the wiki:

http://wiki.xensource.com/xenwiki/Compressing_VM_exports
One implication is that new (compressed) exports will fail to import on old= er servers. However (a) there's an easy workaround (gunzip); and (b) I = think being able to import an old (uncompressed) export on a new server is = more important than the other way around.

Comments appreciated!

Cheers,
Dave



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Xen-devel mailing list
Xen-devel@lists.xensource.= com
http://l= ists.xensource.com/xen-devel

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