Re: [Xen-users] "xm save" hanging when saving domain in "pause" state

[Michael Vrable <mvrable@xxxxxxxxxxx>]

On Thu, Jul 13, 2006 at 10:32:47PM -0700, Claris Castillo wrote:
> Is there any known issue on saving a domain which is in pause state?
> Xen hangs whenever I try to save (by means of xm save command) the state of
> a machine which has been paused (by means of xm pause command). I have been
> looking at the log files etc but I am not able to spot the problem. BTW, xm
> save works prefectly fine if the domain is running or block. The problem is
> when the domain is in pause.

Yes, this is by design.  Save/restore are a cooperative process:
 1. Xend notifies the domain that it will be saved
 2. The domain disconnects from devices, places itself into a quiescent
    state, and notifies Xen
 3. After receiving this notification, xend saves the domain's CPU state
    and memory to a file
Pausing a domain will prevent any progress from being made on step 2
(for the obvious reason--the domain can't run), so saving will hang.

--Michael Vrable

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