[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: [Xen-users] Xen Live Migration


  • To: <xen-users@xxxxxxxxxxxxxxxxxxx>
  • From: "[STD]Ein" <ein@xxxxxxxxxxxxxx>
  • Date: Sun, 20 Jan 2008 04:31:37 -0600
  • Delivery-date: Sat, 19 Jan 2008 14:28:50 -0800
  • List-id: Xen user discussion <xen-users.lists.xensource.com>
  • Thread-index: AchaYrRmRzBuA/fUQvm04+SgJu52mwA69/MA

Using an lvm manager that supports snapshotting (copy on write), and periodically syncing ‘base’ volumes between hosts would probably be the best way to manage this.  Downside is that you now have the overhead of snapshots, plus maintain a full copy of the disk image on both machines involved.  The benefit is that on migration, you only need to transfer the cow snapshot which would typically be much smaller, not a good option for, a fileserver for example, but a webserver that has mostly static content would be an ideal candidate, where the changes on a daily basis might only be in the 10’s of megabytes.  As to a premade tool to do this, there is none that I know of, but afaik there is places to hook in to run such a script.  Be aware, that even with a ‘fast’ method like this, you’ll probably extend the downtime considerably.

 


From: xen-users-bounces@xxxxxxxxxxxxxxxxxxx [mailto:xen-users-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of Todd Deshane
Sent: January 19, 2008 12:15 AM
To: Andrew McCormack
Cc: xen-users@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-users] Xen Live Migration

 

 

On Jan 10, 2008 1:42 PM, Andrew McCormack <merlinn@xxxxxxxxx> wrote:

I'm a little confused as to what I've found regarding Live Migration.  Is it true that there is a central file system accessible to both hosts and that all that is transferred is the current MEMORY contents of the domain?


That is the basic idea yes.

 

  If this is true, is there no way to physically transfer the domain file system from one host to another?  Thanks.


In theory this could be done, but would require a lot more overhead. I can't recall if there is any work with Xen on this or not. I believe OpenVZ, which virtualizes at a layer higher (the operating system), has support for live migration without the central file system.


Regards,
Todd
 


-Andrew

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users

 

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users

 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.