[pve-devel] HA Migration on shutdown/reboot

[Bastian Sebode]

Hello Proxmox Team,

I'm wondering why there is no option "migrate" for the shutdown_policy
available.

I looked a bit through the code and found create_migrate_worker() in
PVE/API2/Nodes.pm, which is used in mass migration. Can't this be used
in PVE/HA/LRM.pm when shutdown_policy = "migrate"?

You know that servers take from 1 to 10 minutes to reboot. So the
interruption by freezing, shutting down and starting on another node in
HA setup seems not logic to me and will take a long time to recover the
service.
-> shutdown of databases, mounts, guest os
-> shutdown of host
-> start on other host

Migration would keep the service running all the time - I guess in HA
activated Environments online migration is mostly possible - and would
also accelerate the shutdown of the host, because the VMs don't have to
shut down on that host.

Defining the Target Node could rely on the HA Groups priority and if not
in HA you could still freeze and shutdown a VM or migrate to least used
node - I remember Thomas already wrote about this and the problems
behind - or even ask where to migrate.

Right now the only way to keep services in HA online all the time
through a node reboot, is to change the HA Group, so the service gets
correctly migrated by crm. But that also has to be undone after the reboot.

Okay, right now LXC came to my mind... I know there's no online
migration, but am speaking for KVM now. ;-) Freeze is also applicable here.

Probably it's not that easy to implement as I think on top, but do you
already think of a feature like this? Or is there any other way to
update my HA activated Cluster without service downtime and without the
HA Group changing?

Thanks so far for PVE! <3
Peace
Bastian

-- 
Bastian Sebode
Fachinformatiker Systemintegration

LINET Services GmbH | Cyriaksring 10a | 38118 Braunschweig
Tel. 0531-180508-0 | Fax 0531-180508-29 | http://www.linet-services.de

LINET in den sozialen Netzwerken:
www.twitter.com/linetservices | www.facebook.com/linetservices
Wissenswertes aus der IT-Welt: www.linet-services.de/blog/

Geschäftsführung: Timo Springmann, Mirko Savic und Moritz Bunkus
HR B 9170 Amtsgericht Braunschweig

USt-IdNr. DE 259 526 516