RELEASE                                                   CMS Transient command

Use the RELEASE command to free an accessed disk and make the files on it
unavailable.  The format of the RELEASE command is:
+----------+------------------------------------------------------------------+
| RELease  | cuu|mode [(DET[)]]                                               |
+----------+------------------------------------------------------------------+
where:

cuu      is the virtual device address of the disk that is to be released.
         Valid addresses are 001 through 5FF for a virtual machine in basic
         control mode and 001 through FFF for a virtual machine in extended
         control mode.

mode     is the mode letter at which the disk is currently accessed.

Option:

DET      specifies that the disk is to be detached from your virtual machine
         configuration; CMS calls the CP command DETACH.


Usage notes:

1.  If a disk is accessed at more than one mode letter, the RELEASE cuu command
    releases all modes.  If you access a disk specifying the mode letter of an
    active disk, the first disk is released.

2.  You cannot release the system disk (S-disk).

3.  When a disk is released, the user file directory is freed from storage and
    that storage becomes available for other CMS commands and programs.  When
    you release a read/write CMS disk, either with the RELEASE command or
    implicitly with the FORMAT command or ACCESS commands, the user file
    directory is sorted and rewritten on disk; user(s) who may subsequently
    access the same disk may have a resultant favorable decrease in file search
    time.

4.  When a disk is released, any read-only extensions it may have are not
    released.  The extensions may be referred to by their own mode letters.  If
    a disk is then accessed with the same mode as the original parent disk, the
    original read-only extensions remain extensions to the new disk at that
    mode.

5.  In CMS/DOS, when you release a disk, any system or programmer logical unit
    assignments made for the disk are unassigned.

Responses:

DASD cuu DETACHED
     This is a CP message that is issued when you use the DET option.  It
     indicates that the disk has been detached.