Cisco DS-C9216I-K9 Configuration Manual page 318

Configuring iSCSI
The failover to secondary port is done transparently by the IPS port without impacting the iSCSI session
from the host. All outstanding I/O are terminated with a check condition status when the primary port
fails. New I/O received while the failover has not completed will receive a busy status.
Tip If you use LUN mapping, you can define a different secondary Fibre Channel LUN if the LU number is
different.
Refer to the Cisco MDS 9000 Family Configuration Guide for details on setting the secondary pWWN.
Enable the revert to primary port option to direct the IPS port to switch back to the primary port when
the primary port is up again. If this option is disabled (default) and the primary port is up again after a
switchover, the old sessions will remain with the secondary port and does not switch back to the primary
port. However, any new session will use the primary port. This is the only situation when both the
primary and secondary ports are used at the same time.
To enable the revert to primary port option, follow these steps:
Choose End Devices > iSCSI from the Physical Attributes pane in Fabric Manager, or choose IP >
Step 1
iSCSI from Device Manager. You see the iSCSI tables in the Fabric Manager Information pane, or the
Device Manager iSCSI dialog box.
Step 2 Click the Targets tab to display a list of existing iSCSI targets.
Step 3 Check the RevertToPrimaryPort check box to enable this option.
Set the iSCSI target node name in the iSCSI Name field, in IQN format.
Step 4
Click the Apply Changes icon in Fabric Manager (or click Apply in Device Manager) to save this
Step 5
change, or click Cancel to close the dialog box without saving any changes.
Configuring the Trespass Feature
In addition to the high availability of statically imported iSCSI targets, the trespass feature is available
(effective Release 1.3(x)) to enable the export of LUs, on an active port failure, from the active to the
passive port of a statically imported iSCSI target.
In physical Fibre Channel targets, which are configured to have LUs visible over two Fibre Channel
N-ports, when the active port fails, the passive port takes over. Some physical Fibre Channel targets
require that the trespass command be issued, to export the LUs from the active port to the passive port.
A statically imported iSCSI target's secondary pWWN option and an additional option of enabling the
trespass feature is available for a physical Fibre Channel target with redundant ports. When the active
port fails, the passive port becomes active, and if the trespass feature is enabled, the MDS issues a
trespass command to the target to export the LUs on the new active port. The iSCSI session switches to
use the new active port and the exported LUs are accessed over the new active port.
Cisco MDS 9000 Fabric Manager Switch Configuration Guide
24-30
Chapter 24 Configuring IP Storage
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