- Clustered Data ONTAP 8
During normal operations, there is no need for SAN logical interfaces (LIFs) to move from one cluster node or physical port to another, but there are several circumstances in which non-disruptive migration of LIFs might be required:
- Replacing an HA pair of a clusters with an upgraded HA pair so that it transparent to the hosts accessing the LUN data
- Upgrading a target interface card to a faster or more capable model
- Shifting a Vserver’s resources from a set of nodes in a cluster to another
In this way, the administrative burden of rezoning a Fibre Channel fabric or creating new iSCSI sessions between a cluster’s attached hosts and its new target interface can be avoided.
Unlike logical interfaces with NAS protocols, an LIF that has been assigned a SAN data protocol cannot be migrated by running the
network interface migrate command. However, if the LIF is brought offline first, it can be modified to have a different home node or port, and brought online again, thus resuming I/O in its new location. This does involve an interruption in I/O on the LIF to be moved, but since redundant paths and automatic path selection through ALUA are part of any clustered ONTAP SAN solution; this should simply cause hosts to retry and then move I/O to another LIF.