SANRAD I3.1.1205 - Manual (Page 88)

5-8 SANRAD V-Switch CLI User Manual
Working with SCSI Storage Devices
The V-Switch default SCSI bus ID is 7. If your storage cluster includes SCSI
storage devices, one of the V-Switch’s default SCSI bus ID may need to be
changed, depending on the number of internal bus drives in the attached SCSI
storage system. Consult your SCSI system manual to verify if your SCSI device
has one or two internal buses. If your SCSI device has one internal bus, both V-
Switches in the cluster will be sharing the same bus. Therefore, you have to
change the SCSI bus ID of one of the V-Switches. The V-Switch SCSI port also
includes a SCSI bus terminator. If both V-Switches are on the same SCSI bus,
you need to eliminate the storage device internal terminator, if present.
Use the CLI command pscsi set busid to change the SCSI bus ID on one
of the V-Switches.
pscsi set busid
S WITCH P ARAMETER D EFINITION S TATUS E XAMPLE
-if INTERFACE STORAGE PORT
NUMBER
/ ALIAS
MANDATORY pscsi3
-id ID P SCSI ID NUMBER
BETWEEN 0 AND 15
MANDATORY 12
Example
pscsi set busid if pscsi3 –id 12
Maintaining Cluster Communications
Once a V-Switch knows that it has a neighbor, it begins sending out a regular
keep alive signal to its neighbor that it is on-line. The V-Switch also begins
listening for the keep alive signal from its neighbor. The keep alive signal is
transmitted through all connecting paths between each neighbor. Thus, if one
path fails, the remaining path(s) will still carry the keep alive signal.
If a specified time period passes without a keep alive signal from the neighbor,
a suspicious interval, measured in seconds, is entered. The V-Switch suspects
that its neighbor has gone off-line and begins preparing to activate the neighbor
IP addresses to take over volume exposure.
If a keep alive signal is received during the suspicious interval, the timer is reset
and the V-Switch continues to function as usual. If a keep alive signal is not
received by the end of the suspicious interval, a dead interval is entered. At the
end of the dead interval, the neighboring V-Switch is considered off-line, the
failover process is initiated and the on-line V-Switch actives the neighbor IP
addresses and takes over volume exposure.