Cleaning the staging disk

When a stage command is issued, the stage program checks to see how much space exists on the staging disk. If there is insufficient space, it signals a cleanup process and waits until enough space has been freed.

This cleanup process should be permanently running and is started by running the STAGECLN command file, e.g. at system startup.

The STAGECLN program takes out a lock on a resource named STAGEPURGER. It establishes a blocking AST routine which is fired whenever a user issues a STAGE command that requires more disk space than is currently available on the staging disk.

The program then spawns a subprocess which then executes the command file CLEANSTAGE.COM. This command file performs the following actions.

1. Illegal files are deleted from the staging disk
2. It then deletes files older than a specified time.
3. If enough space is recovered, it exist, otherwise the lifetime is decreased and the process repeated.

There are a number of parameters that can be set to control the action of this command file. These are shown below.

             Configuring the CLEAN-STAGE command file
                                  

$ !
$ !    The following settings are for VXCERN...
$ !
$      days     = "7"      ! Start by deleting files older than DAYS days
$      hours    = "23"     ! then switch to hours when DAYS < 1
$      max_pass = 15       ! Maximum number of passes
$ !
$ !    Deletion is done on creation date. To delete according to
$ !    file usage do:
$ !
$ !    SET VOLUME/RETENTION=(1,1-) DISK$STAGE
$ !
$ !    This means that, when files are created, the expiry date is set
$ !    to now plus one day. On each access, 1 hour is added to the current
$ !    time. If this is greater than the current expiry date then the expiry
$ !    date is reset.
$ !
$ !    Then, change DELETE/CREATED/SINCE to
$ !                 DELETE/EXPIRED/BEFORE
$ !    which deletes files whose expiry date is BEFORE the specified
$ !    date & time
$ !