Hi Alain,

  For live migration, you have to make the logical volume both
available to the source
and the target server in the same time.

  So you have to use either cLVM/cEVMS or plain disk.

2008/5/30 Alain St-Denis <[EMAIL PROTECTED]>:
> Hello,
>
> Since nobody paid attention to my first post, here I am again with more
> details...
>
> I modified the LVM RA so it works on logical volumes instead of volume groups
> and made it a master/slave RA. The goal is to use heartbeat to control
> logical volume activation (we are using shared disks and gave up on cluster
> lvm) to guard ourselves against human or software error. My RA makes the
> logical volumes it controls available on one node only (one master, x
> slaves). It is working as I expect in situations involving start and stop
> actions, but I am scratching my head trying to figure out how to take
> advantage of the xen live migration feature. The following constraints don't
> do the job:
>
> <rsc_order id="order_xen_start" from="resource_xen" to_action="promote"
> to="master_lvs"/>
>   <rsc_order id="order_xen_migrate" from="resource_xen" to_action="promote"
> to="master_lvs" action="migrate_to" symmetrical="false"/>
>   <rsc_colocation id="xen_with_master_lvs" to_role="Master"
> from="resource_xen" to="master_lvs" from_role="Started" score="INFINITY"
> symmetrical="false"/>
>
> If I issue a migrate on resource_xen, I see this from pengine
>
> pengine: [13220]: notice: complex_migrate_reload: Migrating resource_xen from
> sss4 to sss3
>
> which is encouraging. But at the same time, tengine says:
>
> tengine: [13219]: ERROR: te_graph_trigger: Transition failed: terminated
>
> which can't be a good sign.
>
> The master_lvs resource has
>
> clone_max = 2
> clone_node_max = 1
> master_max = 1
> master_node_max =1
>
> I have the feeling "master_max = 1" is not helping. If I set master_max to 2
> and remove the colocation constraint above, live migration works. But this is
> not what I want. Is there a way to tell a master/slave resource that its
> master_max is 2 but only 1 will be promoted most of the time?
>
> BTW, this is with 2.1.3 and pacemaker 0.6.2.
>
> Thanks
>
> Alain
>
> Le lundi 26 mai 2008 12:44, Alain St-Denis a écrit :
>> Hello Linux-HA,
>>
>> I would like to set up two resources, one of which is a xen guest and the
>> other is a LVM2 logical volume, lets call them xenA and resB, where xenA
>> depends on resB. I can figure out how to set up the appopriate co-location
>> and order constraints for the start and stop actions, but what about
>> migrate_to and migrate_from? While live migration occurs, two instances of
>> resB must be running. The RA associated with resB only does "lvchange -a y
>> LV" on start and "lvchange -a n LV" on stop.
>>
>> If anyone can send pointers on how to achieve the following:
>>
>> xenA and resB are running on node1
>> a live migration is initiated to node2
>> resB starts on node2 but keeps running on node1
>> xenA migrates to node2
>> resB is stopped on node1
>> xenA and resB are running on node2
>>
>> I'd appreciate it. Any information on how the migrate_to and migrate_from
>> actions are implemented would also be useful. It seems to me defining those
>> actions for the resB RA may be the thing to do, as long as co-location and
>> order constraints can be set for those actions.
>>
>> Thanks in advance,
>>
>> Alain
>
> --
> Alain St-Denis
> Supercomputing, Systems and Storage
> Canadian Meteorological Centre
> Meteorological Service of Canada
> Environment Canada
> Tel: +1 514 421 4697
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> See also: http://linux-ha.org/ReportingProblems
>
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