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Hi All,<br>
<br>
I am using a simple two-nodes cluster with Xen on top of DRBD in
primary/primary mode (necessary for live migration). My
configuration is quite simple:<br>
<br>
primitive appyul1 ocf:heartbeat:Xen \<br>
params xmfile="/etc/xen/appyul1.cfg" shutdown_timeout="299"
\<br>
op monitor interval="10s" timeout="300s" \<br>
op start interval="0s" timeout="180s" \<br>
op stop interval="0s" timeout="300s" \<br>
op migrate_from interval="0s" timeout="180s" \<br>
op migrate_to interval="0s" timeout="180s" \<br>
meta target-role="Started" allow-migrate="true"
is-managed="true"<br>
primitive appyul1slash-DRBD ocf:linbit:drbd \<br>
params drbd_resource="appyul1slash" \<br>
operations $id="appyul1slash-DRBD-ops" \<br>
op monitor interval="20s" role="Master" timeout="300s" \<br>
op monitor interval="30s" role="Slave" timeout="300s"<br>
primitive appyul1swap-DRBD ocf:linbit:drbd \<br>
params drbd_resource="appyul1swap" \<br>
operations $id="appyul1swap-DRBD-ops" \<br>
op monitor interval="20s" role="Master" timeout="300s" \<br>
op monitor interval="30s" role="Slave" timeout="300s"<br>
ms appyul1slash-MS appyul1slash-DRBD \<br>
meta master-max="2" notify="true" interleave="true"
target-role="Started" is-managed="true"<br>
ms appyul1swap-MS appyul1swap-DRBD \<br>
meta master-max="2" notify="true" interleave="true"
target-role="Started" is-managed="true"<br>
order appyul1-after-drbd inf: appyul1slash-MS:promote
appyul1swap-MS:promote appyul1:start<br>
<br>
So to summerize:<br>
- A resource for Xen<br>
- Two Master/Slave DRBD ressources for the VM filesystem (/ and
swap). master-max is set to 2 to have both node in primary DRBD
state.<br>
- a "order" directive to start the VM after drbd has been promoted.<br>
<br>
Node startup is ok, the VM is started after DRBD is promoted. <br>
<br>
Node shutdown is problematic. Assuming the Xen VM runs on node A :<br>
- When puting node A in standby when node B is active, a live
migration is started, BUT in the same second, pacemaker tries to
demote DRBD volumes on A (while live migration is in progress).<br>
- When putting node A in standby when node B is also in standby, the
VM is stopped, BUT in the same second, pacemaker tries to demote
DRBD volumes on A (while shutdown is still in progress).<br>
<br>
All this results in "failed actions" in the CRM, and cause unwanted
stonith actions (when enabled). I tried to add "symmetrical=false"
on the order constraint, but it did not help.<br>
<br>
I do not understand by pacemaker does not wait the Xen VM is
stopped/migrated before demoting DRBD volumes.<br>
<br>
Setup is done with corosync and pacemaker packages available on a
standard Ubuntu Lucid (corosync 1.2.0 and pacemaker 1.0.8).<br>
<br>
Thanks for your help,<br>
<br>
Pierre<br>
<br>
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