EMC CLARiiON Asymmetric Active/Active Feature (ALUA) - A Detailed Review
The Asymmetric Active/Active feature within FLARE release 26 increases configuration flexibility and investment protection for a changing environment, and provides increased availability for systems. Asymmetric Active/Active is an emerging SCSI standard. It supports host failover methods that adhere to this specification. Hosts can now avoid unwanted trespassing in certain scenarios, as I/O can be redirected to the SP that owns the LUN The back-end fault masking feature is provided to all Failover Mode types. In the case of a back-end failure on the SP that is the current owner of the LUN. I/O is routed via the lower redirector of the peer SP with the stable back end. This avoids trespassing. which can often impede replication operations.