HP StorageWorks IP Storage Router - Manual (Page 191)

Maintaining and Managing the Storage Router
191 IP Storage Router SR2122-2 User Guide
Once a SCSI routing instance has been stopped, it can be re-activated by issuing
the scsirouter enable command. The scsirouter enable command
must be issued from the same storage router as the no scsirouter enable
command.
See the IP Storage Router 2122-2 Command Line Interface User Guide for
command details.
Viewing Operational Statistics
Use the show scsirouter stats command to display the status of the
SCSI routing instance and to see the number of active connections and the number
of logins that have occurred since the storage router was last restarted (or since
statistics were last cleared).
For example, the show scsirouter stats command in Example 22 shows
that SCSI routing instance, foo, is currently active.
Example 22: Results of “show scsirouter stats” Command
[SR2122-2_PR1]# show scsirouter foo stats
router status started iSCSI ver (Min/Max)
logins active
foo ACTIVE Jan 11 23:06:08 2/2
10 7
Handling Failover
In a cluster, storage routers continually exchange information as heartbeats to
detect failures in the cluster. HA messages are sent using UDP over IP and,
depending on the message type or situation, may be sent as unicast or multicast
messages. To make sure that HA information is exchanged reliably between
storage routers, the storage routers alternate transmission of heartbeats between
the management and the HA interfaces.
Failover of SCSI routing instances is automatic when the storage router detects
that another storage router in the cluster is no longer responding to heartbeats.
Failover of a SCSI routing instance also occurs if the associated Gigabit Ethernet
interface is unavailable or if all targets are unavailable.