Cluster Communications Control Tools and Utilities?
In most OpenVMS versions, you can use the tools: o SYS$EXAMPLES:LAVC$STOP_BUS o SYS$EXAMPLES:LAVC$START_BUS These tools permit you to disable or enable all SCS traffic on the on the specified paths. You can also use a preferred path mechanism that tells the local MSCP disk class driver (DUDRIVER) which path to a disk should be used. Generally, this is used with dual-pathed disks, forcing I/O traffic through one of the controllers instead of the other. This can be used to implement a crude form of I/O load balancing at the disk I/O level. Prior to V7.2, the preferred path feature uses the tool: o SYS$EXAMPLES:PREFER.MAR In OpenVMS V7.2 and later, you can use the following DCL command: $ SET PREFERRED_PATH The preferred path mechanism does not disable nor affect SCS operations on the non-preferred path. With OpenVMS V7.3 and later, please see the SCACP utility for control over cluster communications, SCS virtual circuit control, port selection, and related.
