Understanding DASD volume status information

To determine the devices that are present in the MVS system with valid paths, choose Monitor > SSI monitor from the File List panel in the XBM ISPF interface. The resulting SSI Objects panel displays the status of all of the devices that were discovered during startup (unless View filtering is active). If any expected devices are not included, it is likely that XBM did not discover them during its initialization.

When the SSI component starts, it attempts to discover all of the DASD accessible to the MVS image. To be found, a device must be genned with a valid unit control block (UCB) and at least one validated path to the device must exist. If no path exists, no discovery I/O is issued, which avoids a very long delay on each UCB for path validation or truly absent devices.

Devices used as mirrors are sometimes genned as offline devices, which means that path validation does not occur during an Initial Program Load (IPL), and consequently XBM does not find them during discovery. In these cases, you can use the Devserv Path command after an IPL to identify the range of general devices that are offline. Executing this command allows XBM to find these devices during the subsequent discovery, so that you can display them in the XBM monitor and use them for snapshot or other mirroring activity.

The following example shows the syntax for the Devserv Path command.