What is the Role of EMC Clariion Access Logix ?

On a CLARiiON storage system without Access Logix installed, or on a storage system where Access Logix is installed but not yet enabled, all CLARiiON LUNs are presented to all storage system ports. Any host that connects to the storage system will then have access to all of the LUNs on that storage system. In environments where multiple hosts attach to the storage system, this may cause problems. Windows systems may attempt to take ownership of LUNs belonging to other Windows systems, and Unix systems may try to mount Windows LUNs, for example. In addition to this, security is compromised because of the lack of access control. Access Logix solves these problems by performing LUN masking – it masks certain LUNs from hosts that are not authorized to see them, and presents those LUNs only to the server(s) which are authorized to see them. In effect, it present a ‘virtual storage system’ to each host – the host sees the equivalent of a storage system dedicated to it alone, with only its own LUNs visible to it.

Another task which Access Logix performs is the mapping of CLARiiON LUNs, often called FLARE LUNs or FLUs, to host LUNs. It will determine which physical addresses, in this case the device numbers, each attached host will use for its LUNs. Note that this feature is configurable by the user through the CLI and the GUI. Access to LUNs is controlled by information stored in the Access Logix database, which is resident in a reserved area of CLARiiON disk - the PSM LUN. The Access Logix software manages this database.When host agents in the CLARiiON environment start up, typically shortly after host boot time, they send initiator information to all storage systems they are connected to. This initiator information is stored in the Access Logix database.

Salient Features:-

1) LUN masking.

2) Presents a virtual storage system.

3) Maps CLARiiON LUNs (FLARE LUNs) to host LUNs.

4) Manages the Access Control List.

5) Manages Initiator Registration Records.

Access Logix database entries.