Administration Guide › Managing CA VM:Director › Servant Facility

Servant Facility

The Servant Facility is a set of special worker virtual machines that help CA VM:Director perform long–running CMS tasks such as formatting and copying minidisks, and deleting and renaming SFS file spaces.

These extra worker virtual machines, or servant machines, let directory managers start minidisk management functions and continue to work while the minidisk management functions are processed. They save time and increase productivity.

You can use the Servant Facility whenever your staff has many minidisk management functions to perform; you can turn the Servant Facility off and on at any time.

Note: You must use the Servant Facility if you are using CA VM:Director for SFS administration and want to use the DELETE and CHANGE commands. With the Servant Facility, potentially long–running commands can execute on an CA VM:Director servant instead of tying up the CA VM:Director service virtual machine.

When the Servant Facility is turned on, CA VM:Director dynamically creates and autologs servant user IDs when it needs them. It creates as many servant virtual machines as it requires, up to the limit you choose or up to 9999, whichever is smaller.

Servant user IDs are created in the range VMX$0001 to VMX$9999 by default (you can change the first four characters of their user IDs). CA VM:Director uses its own directory entry as a prototype for the directory entries for these servant user IDs, and, as for all directory entries created from prototypes, it strips all minidisk references from each new directory entry and changes the user ID, password, and other statements as necessary.

Note: The servant user IDs are created with a maximum virtual storage (vstor) size of 24M. Additionally, because the servant user IDs are modeled after the VMDIRECT directory entry, you cannot have an IPL 190 statement in the CA VM:Director service virtual machine’s directory entry.

When CA VM:Director requires a servant for a process, it places the process in a wait queue and searches for an available servant. If it finds an available servant, it attaches that servant to the process and places the process in the ready queue. If it cannot find an available servant, it creates a directory entry for a new servant and adds the entry to the object directory. It then autologs the new servant, attaches the servant to the process, and places the process in the ready queue.

When a process finishes with a servant, it releases the servant. CA VM:Director then removes any links that were made during the processing and verifies the number of free servant user IDs against the number that must remain standing by. If there are more free servant user IDs than required, CA VM:Director logs off the extra ones.

You define the characteristics of the Servant Facility, including the number of free servants that can remain waiting and the maximum number of servants that can exist, through the SERVANT record. This record exists in the PRODUCT CONFIG file.

Note: For more information about defining Servant Facility characteristics, see SERVANT Record in the chapter "Configuration File Reference" in the Reference Guide.