SAL (SAN Access Layer) A component that performs discovery and access control. By discovering objects and the relationship of these objects to each other, SAL maintains a real-time topology of the storage network or SAN. SAL also interacts directly with switches and storage arrays to control access to storage resources. The SAL agent—part of SAL—communicates with client applications by sending and receiving XML messages by means of the http protocol. SAL has a command-line interface called vxsalcmd with which you can connect to a SAL server to manage a discovery data store by issuing commands to manage zones, manage user accounts, and query data.