How to detect completion of a paused VM migration on the destination?
Hi, when a normally running VM is migrated, libvirt sends VIR_DOMAIN_EVENT_RESUMED_MIGRATED event on the destination once the migration completes. I can see that when a paused VM is migrated, libvirt sends VIR_DOMAIN_EVENT_SUSPENDED_PAUSED instead. Since there seems to be nothing migration specific about VIR_DOMAIN_EVENT_SUSPENDED_PAUSED event, my question is: Is it safe to assume on the destination that this event signals completion of the incoming migration (unless VIR_DOMAIN_EVENT_RESUMED_MIGRATED is received before)? Thanks, Milan
On 1/21/20 3:28 PM, Milan Zamazal wrote:
Hi,
when a normally running VM is migrated, libvirt sends VIR_DOMAIN_EVENT_RESUMED_MIGRATED event on the destination once the migration completes. I can see that when a paused VM is migrated, libvirt sends VIR_DOMAIN_EVENT_SUSPENDED_PAUSED instead.
Since there seems to be nothing migration specific about VIR_DOMAIN_EVENT_SUSPENDED_PAUSED event, my question is: Is it safe to assume on the destination that this event signals completion of the incoming migration (unless VIR_DOMAIN_EVENT_RESUMED_MIGRATED is received before)?
Yes. This is the code that handles the finish phase of migration: https://libvirt.org/git/?p=libvirt.git;a=blob;f=src/qemu/qemu_migration.c;h=... which can be read as the following pseudo code: if (postCopy) sendEvent(VIR_DOMAIN_EVENT_RESUMED_MIGRATED); if (domain.paused) sendEvent(VIR_DOMAIN_EVENT_SUSPENDED_PAUSED); Michal
Michal Privoznik <mprivozn@redhat.com> writes:
On 1/21/20 3:28 PM, Milan Zamazal wrote:
Hi,
when a normally running VM is migrated, libvirt sends VIR_DOMAIN_EVENT_RESUMED_MIGRATED event on the destination once the migration completes. I can see that when a paused VM is migrated, libvirt sends VIR_DOMAIN_EVENT_SUSPENDED_PAUSED instead.
Since there seems to be nothing migration specific about VIR_DOMAIN_EVENT_SUSPENDED_PAUSED event, my question is: Is it safe to assume on the destination that this event signals completion of the incoming migration (unless VIR_DOMAIN_EVENT_RESUMED_MIGRATED is received before)?
Yes. This is the code that handles the finish phase of migration:
https://libvirt.org/git/?p=libvirt.git;a=blob;f=src/qemu/qemu_migration.c;h=...
which can be read as the following pseudo code:
if (postCopy) sendEvent(VIR_DOMAIN_EVENT_RESUMED_MIGRATED);
if (domain.paused) sendEvent(VIR_DOMAIN_EVENT_SUSPENDED_PAUSED);
OK, thank you for clarification. Regards, Milan
participants (2)
-
Michal Privoznik -
Milan Zamazal