Failing Back A File Serving Node; Using Network Interface Monitoring - HP IBRIX X9720 System Administrator Manual

2. Determine whether the failover was successful:
ibrix_server -l
The STATE field indicates the status of the failover. If the field persistently shows Down-InFailover
or Up-InFailover, the failover did not complete; contact HP Support for assistance. For information
about the values that can appear in the STATE field, see
(page 38).

Failing back a file serving node

After automated or manual failover of a file serving node, you must manually fail back the server,
which restores ownership of the failed-over segments and network interfaces to the server. Before
failing back the node, confirm that the primary server can see all of its storage resources and
networks. The segments owned by the primary server will not be accessible if the server cannot
see its storage.
To fail back a file serving node, use the following command, where the HOSTNAME argument
specifies the name of the failed-over node:
ibrix_server -f -U -h HOSTNAME
After failing back the node, determine whether the failback completed fully. If the failback is not
complete, contact HP Support for assistance.
NOTE: A failback might not succeed if the time period between the failover and the failback is
too short, and the primary server has not fully recovered. HP recommends ensuring that both servers
are up and running and then waiting 60 seconds before starting the failback. Use the
ibrix_server -l command to verify that the primary server is up and running. The status should
be Up-FailedOver before performing the failback.

Using network interface monitoring

With network interface monitoring, one file serving node monitors another file serving node over
a designated network interface. If the monitoring server loses contact with its destination server
over the interface, it notifies the Fusion Manager. If the Fusion Manager also cannot contact the
destination server over that interface, it fails over both the destination server and the network
interface to their standbys. Clients that were mounted on the failed-over server do not experience
any service interruption and are unaware that they are now mounting the file system on a different
server.
Unlike X9000 clients, NFS and CIFS clients cannot reroute file requests to a standby if the file
serving node where they are mounted should fail. To ensure continuous client access to files, HP
recommends that you put NFS/CIFS traffic on a user network interface (see
interfaces" (page
Comprehensive protection of NFS/CIFS traffic also involves setting up network interface monitoring
for the cluster interface. Although the Fusion Manager eventually detects interruption of a file serving
node's connection to the cluster interface and initiates segment failover if automated failover is
turned on, failover occurs much faster if the interruption is detected through network interface
monitoring. (If automated failover is not turned on, you will see file access problems if the cluster
interface fails.) There is no difference in the way that monitoring is set up for the cluster interface
and a user network interface. In both cases, you set up file serving nodes to monitor each other
over the interface.
Sample scenario
The following diagram illustrates a monitoring and failover scenario in which a 1:1 standby
relationship is configured. Each standby pair is also a network interface monitoring pair. When
SS1 loses its connection to the user network interface (eth1), as shown by the red X, SS2 can no
longer contact SS1 (A). SS2 notifies the Fusion Manager, which then tests its own connection with
87)), and then implement network interface monitoring for it.
"What happens during a failover"
"Preferring network
Cluster high availability 41