HP XC System Software Administration Guide Version 3.2

Nodes must be stopped and restarted during the reimaging process.
When a node is reimaged, but its partner in an availability set is still running, the reimaged node
comes under the control of the availability tool automatically.
When both or all the nodes in an availability set are down, you must use the
transfer_to_avail command on the head node to transfer control of services to the availability
tool.
Consider the example of two HP Serviceguard clusters: one comprising nodes n12 and n13, and
the other comprising nodes n14 and n16. Node n16 is the head node. The sequence of events
is as follows:
1. The golden image on node n16 is updated so that the software can be propagated to the
other nodes.
2. Nodes n12, n13, and n14 are stopped so that they can be reimaged.
Node n16 is still running.
3. When node n14 starts up again, it automatically joins its Serviceguard cluster. It does so
because node n16, its partner, is up and running a Serviceguard cluster.
4. When nodes n12 and n13 start up, they do not form their Serviceguard cluster. You must
issue the transfer_to_avail command on the head node to transfer control of services
to their Serviceguard cluster. In this example, the transfer_to_avail command is run
on the head node. This command ignores Serviceguard clusters that are already running
and start the other clusters that are not.
# transfer_to_avail
5. Both nodes, n12 and n13, are up because they are reimaged. The control of their services
is transferred to Serviceguard.
2.5 Transferring Control of Services
The HP XC System Software provides these commands to transfer control of services to and from
the availability tool:
• transfer_to_avail
The transfer_to_avail command transfers the control of services from the HP XC
system to the availability tool.
• transfer_from_avail
The transfer_from_avail command transfers the control of services from the availability
tool back to the HP XC system.
IMPORTANT: You must issue these commands from the head node. Issuing these commands
from a node other than head node may result in these commands hanging and not completing.
The following example shows the output of the transfer_from_avail command to transfer
the control of services from the HP Serviceguard availability tool to the HP XC system:
# transfer_from_avail
Info: Status check for nodes supporting availability:
Info: Node 'n16' up and running
Info: Node 'n14' up and running
Info: Head node 'nh' up and running
Info: Serviceguard-managed services are: 'nat lvs nagios dbserver'
Info: HeartBeat-managed services are: ''
Info: NAT HA servers are: 'n16 n14'
Info: confirming the list of services to transfer from availability...
2.5 Transferring Control of Services 51