Hello Everyone I have been trying to use the xm tool to migrate guest OS from one host to another host. I have setup a NFS storage such that one host can remotely access the disk image files. The output of using xm migrate is as follows: - VM migration is successfully completed. However, xm list output still displays the guest OS on the source host in shutdown state on which it was initially installed. And I can start the guest OS again on the source resulting in the same guest OS running on the source and target. - When I migrate the same guest OS back to the original host on which it was initially installed from host B, xm list on host B does not display the guest OS. Is this a correct behavior that a guest OS will always be listed on the host on which it was initially installed even though it has been migrated to another host? Any suggestions on this would help a great deal. - Anoop _______________________________________________ Xen-users mailing list Xen-users@lists.xen.org http://lists.xen.org/xen-users
On Fri, Mar 30, 2012 at 10:51 AM, Anoop R. <anoopchalil@gmail.com> wrote:> Hello Everyone > > I have been trying to use the xm tool to migrate guest OS from one host to > another host. I have setup a NFS storage such that one host can remotely > access the disk image files. The output of using xm migrate is as follows: > > - VM migration is successfully completed. However, xm list output still > displays the guest OS on the source host in shutdown state on which it was > initially installed. And I can start the guest OS again on the source > resulting in the same guest OS running on the source and target. > > - When I migrate the same guest OS back to the original host on which it was > initially installed from host B, xm list on host B does not display the > guest OS. > > Is this a correct behavior that a guest OS will always be listed on the host > on which it was initially installed even though it has been migrated to > another host?Yes, IF you use xend-managed config file (i.e. you use "xm new" and "xm start"). This is also the default behavior if you create it using virt-manager or similar frontend. No, if you use plain xen config file (i.e "xm create -f ...") -- Fajar
On Fri, Mar 30, 2012 at 11:01 AM, Anoop R. <anoopchalil@gmail.com> wrote:> Thanks for the response. So does that mean that if I create VM''s using > virt-manager GUI and I migrate guest OS to a different host, the resources > assigned to the guest OS on the original host is not released?No. If you''re REALLY serious is implementing cluster-like setup with shared storage, I HIGHLY recommend you ask the help of an expert. Otherwise, it''s very easy to do something that will damage your system. For example, you said "VM migration is successfully completed. However, xm list output still displays the guest OS on the source host in shutdown state on which it was initially installed. And I can start the guest OS again on the source resulting in the same guest OS running on the source and target." Notice how it was originally on SHUTDOWN state? That is safe. But if you "start the guest OS again on the source resulting in the same guest OS running on the source and target", that is a sure way of corrupting the guest OS filesystem. -- Fajar