HP P6000 Cluster Extension Software Administrator Guide (5697-0986, June 2011)

If you have Secure Path installed and you still cannot see the drive letter when adding the physical
disk resource, you can use the Secure Path command spprutil device to find the mapping between
the Windows physical disk number and the shown partition numbers.
You can add the disk based on this mapping and failover/failback the disk. The correct drive letter
will show up when the disk is brought online on the node where you originally created the disk partition
and drive letter.
The FC link is down (RHCS)
In RHCS, the detection of a storage outage due to failure of all paths to the storage depends on the
monitoring capability of resources configured in the RHCS service. For example, the LVM and filesystem
resource agents distributed with RHCS can detect the loss of storage and take appropriate actions.
The stop operation on a service might fail due to the inability to stop individual resources cleanly.
This may be caused by the loss of paths to the storage. When the stop operation on a service fails,
RHCS marks the service as failed and the service does not automatically fail over to another node.
To recover from this situation, use the following procedure:
1. Remove the node that lost access to the storage by shutting down the node.
2. Follow the steps required to bring up a service in a failed state, as documented in the RHCS
administration guide. This process involves disabling the service, and then enabling it on the
node where the service is allowed to come online.
3. Restart the node that was shut down.
NOTE:
The time to detect a storage outage due to failure of all paths to storage depends on the
setting for no_path_retry in the multipath software configuration. A value of fail does
not queue I/O in the event of a failure in all paths and returns an immediate failure. For
information about the recommended value for your environment, see the DM-Multipath
documentation.
Some resource agents, such as LVM, offer a mechanism called self_fence to take themselves
out of a cluster through node reboot when an underlying logical volume can no longer be
accessed. For supported options, see the RHCS documentation.
A storage replication link is down (RHCS)
If a P6000 Cluster Extension configuration uses DR groups with failsafemode enabled, the array
disables access to the disk when it cannot replicate the I/O to the remote array.
In this situation, if a replication link is broken, the resource agents of configured resources, such as
lvm or fs, may be able to detect and take appropriate actions. The stop operation on a service might
fail due to the inability to stop individual resources cleanly because the disk is no longer accessible
for read/write operations. When the stop operation on a service fails, RHCS marks the service as
failed and the service does not automatically fail over to another node.
To recover from this situation, use the following procedure:
1. Remove the node that lost access to the storage by shutting down the node.
2. Follow the steps required to bring up a service in a failed state, as documented in the RHCS
administration guide. This process involves disabling the service, and then enabling it on the
node where the service is allowed to come online.
HP P6000 Cluster Extension Software Administrator Guide 105