Installation guide

Adding or removing a VM from cluster.conf will not start or stop the VM; it will simply cause
rgmanager to start or stop paying attention to the VM
Failback (moving to a more preferred node) is performed using migration to minimize downtime.
3.5.4 . Unhandled Behaviors
The following conditions and user actions are not supported in RGManager.
Using a non-cluster-aware tool (such as virsh or xm) to manipulate a virtual machine's state or
configuration while the cluster is managing the virtual machine. Checking the virtual machine's
state is fine (e.g. virsh list, virsh dumpxml).
Migrating a cluster-managed VM to a non-cluster node or a node in the cluster which is not
running rgmanager. Rgmanager will restart the VM in the previous location, causing two
instances of the VM to be running, resulting in file system corruption.
3.6. Resource Act ions
RGManager expects the following return values from resource agents:
start - start the resource
stop - stop the resource
status - check the status of the resource
metadata - report the OCF RA XML metadata
3.6.1. Ret urn Values
OCF has a wide range of return codes for the monitor operation, but since rgmanager calls status, it
relies almost exclusively on SysV-style return codes.
0 - su ccess
stop after stop or stop when not running must return success
start after start or start when running must return success
n o n z ero - f ailu re
if the stop operation ever returns a nonzero value, the service enters the failed state and the
service must be recovered manually.
Red Hat Ent erprise Linux 6 High Availabilit y Ad d- O n O verview
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