[ClusterLabs] Early VM resource migration

[Klechomir]

Hi Ken,

I've tried with and without colocation. The rule was:
colocation bla2 inf: VM_VM1 AA_Filesystem_CDrive1

In both cases the VM_VM1 tries to live migrate back the coming after standby 
node while cloned AA_Filesystem_CDrive1 isn't up on it yet.
Same result with pacemaker 1.14-rc2

Regards,

On 16.12.2015 11:08:35 Ken Gaillot wrote:
> On 12/16/2015 10:30 AM, Klechomir wrote:
> > On 16.12.2015 17:52, Ken Gaillot wrote:
> >> On 12/16/2015 02:09 AM, Klechomir wrote:
> >>> Hi list,
> >>> I have a cluster with VM resources on a cloned active-active storage.
> >>> 
> >>> VirtualDomain resource migrates properly during failover (node standby),
> >>> but tries to migrate back too early, during failback, ignoring the
> >>> "order" constraint, telling it to start when the cloned storage is up.
> >>> This causes unnecessary VM restart.
> >>> 
> >>> Is there any way to make it wait, until its storage resource is up?
> >> 
> >> Hi Klecho,
> >> 
> >> If you have an order constraint, the cluster will not try to start the
> >> VM until the storage resource agent returns success for its start. If
> >> the storage isn't fully up at that point, then the agent is faulty, and
> >> should be modified to wait until the storage is truly available before
> >> returning success.
> >> 
> >> If you post all your constraints, I can look for anything that might
> >> affect the behavior.
> > 
> > Thanks for the reply, Ken
> > 
> > Seems to me that that the constraints for a cloned resources act a a bit
> > different.
> > 
> > Here is my config:
> > 
> > primitive p_AA_Filesystem_CDrive1 ocf:heartbeat:Filesystem \
> > 
> >         params device="/dev/CSD_CDrive1/AA_CDrive1"
> > 
> > directory="/volumes/AA_CDrive1" fstype="ocfs2" options="rw,noatime"
> > primitive VM_VM1 ocf:heartbeat:VirtualDomain \
> > 
> >         params config="/volumes/AA_CDrive1/VM_VM1/VM1.xml"
> > 
> > hypervisor="qemu:///system" migration_transport="tcp" \
> > 
> >         meta allow-migrate="true" target-role="Started"
> > 
> > clone AA_Filesystem_CDrive1 p_AA_Filesystem_CDrive1 \
> > 
> >         meta interleave="true" resource-stickiness="0"
> > 
> > target-role="Started"
> > order VM_VM1_after_AA_Filesystem_CDrive1 inf: AA_Filesystem_CDrive1 VM_VM1
> > 
> > Every time when a node comes back from standby, the VM tries to live
> > migrate to it long before the filesystem is up.
> 
> In most cases (including this one), when you have an order constraint,
> you also need a colocation constraint.
> 
> colocation = two resources must be run on the same node
> 
> order = one resource must be started/stopped/whatever before another
> 
> Or you could use a group, which is essentially a shortcut for specifying
> colocation and order constraints for any sequence of resources.
> 
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