[ClusterLabs] manner in which cluster migrates VirtualDomain - ?

[lejeczek]

On 18/04/2023 18:22, Ken Gaillot wrote:
> On Tue, 2023-04-18 at 14:58 +0200, lejeczek via Users wrote:
>> Hi guys.
>>
>> When it's done by the cluster itself, eg. a node goes 'standby' - how
>> do clusters migrate VirtualDomain resources?
> 1. Call resource agent migrate_to action on original node
> 2. Call resource agent migrate_from action on new node
> 3. Call resource agent stop action on original node
>
>> Do users have any control over it and if so then how?
> The allow-migrate resource meta-attribute (true/false)
>
>> I'd imagine there must be some docs - I failed to find
> It's sort of scattered throughout Pacemaker Explained -- the main one
> is:
>
> https://clusterlabs.org/pacemaker/doc/2.1/Pacemaker_Explained/html/advanced-options.html#migrating-resources
>
>> Especially in large deployments one obvious question would be - I'm
>> guessing as my setup is rather SOHO - can VMs migrate in sequence or
>> it is(always?) a kind of 'swarm' migration?
> The migration-limit cluster property specifies how many live migrations
> may be initiated at once (the default of -1 means unlimited).
But if this is cluster property - unless I got it wrong, 
hopefully - then this govern any/all resources.
If so, can such a limit be rounded down to RA type or 
perhaps group of resources?

many thanks, L.