Changing Information on CP-Accessed Minidisks

If your system configuration file contains a FEATURES statement that instructs CP to construct log messages from information in files on CP-accessed minidisks, you can no longer use the SET LOGMSG command to alter the contents of the log message. Instead, you must do the following:

  1. Issue a CPRELEASE command to have CP remove the minidisk from its list of accessed disks.
  2. Issue the CP LINK command and CMS ACCESS command to link and access the target minidisk in write mode.
  3. Edit the files that contain the log messages for your system.
  4. Issue the CMS RELEASE command and the CP DETACH command to release the minidisk and detach it from your virtual machine.
  5. Issue a CPACCESS command to have CP add the minidisk to its list of accessed disks.

Even though you could have CP maintain read-only access to the disk while you are editing the files, it is recommended that you remove the disk from CP's list of accessed disks first. When CP accesses a minidisk, it reads the minidisk's file directory into storage. Any subsequent changes to the minidisk are not reflected into the file directory CP keeps in storage until you issue a CPACCESS command to have CP reaccess the minidisk. If you change files on the minidisk while CP has access to it, users may receive incorrect output in response to commands such as QUERY LOGMSG.

On the other hand, you may encounter another problem if you tell CP to remove the minidisk from its list of accessed minidisks before you make your change. If the minidisk you are changing is the only one that contained log message information, and a user issued a QUERY LOGMSG command while you were in the process of changing the log message, CP would find no log message files and would respond that no log message data existed.

For example, 
query cpdisks
 
Label  Userid   Vdev Mode Stat Vol-ID Rdev Type   StartLoc     EndLoc
PROD1  MAINT    0300  A   R/O  ESARES 0A0F ECKD       2400       2449
Ready;
 
cprelease a
CPRELEASE request for disk A scheduled.
Ready;
CPRELEASE request for disk A completed.
 
query logmsg
There is no logmsg data
Ready;

It is recommended that to change the contents of minidisks that are accessed by CP, you should work with at least two disks. When you instruct CP to release one minidisk in order to change files on the minidisk, CP can still read information from the second minidisk.

For example: 
query cpdisks
 
Label  Userid   Vdev Mode Stat Vol-ID Rdev Type   StartLoc     EndLoc
PROD1  MAINT    0300  A   R/O  ESARES 0A0F ECKD       2400       2449
BACKUP MAINT    0301  B   R/O  ESARES 0A0F ECKD       2450       2499
Ready;
 
cprelease a
CPRELEASE request for disk A scheduled.
Ready;
CPRELEASE request for disk A completed.
 
link maint 300 300 wr
Ready;
 
access 300 a
Ready;
 
xedit system logmsg a
Ready;
 
release a (detach
Ready;
 
cpaccess maint 300 a
CPACCESS request for mode A scheduled.
Ready;
CPACCESS request for MAINT's 0300 in mode A completed.

You can now tell CP to release the B disk (MAINT's 301) and update it to contain the new SYSTEM LOGMSG file that you placed on MAINT's 300 disk.

You can update logo picture files, input area files, and online message files in a similar manner. CP uses the changed files as soon as the CPACCESS request for the minidisk completes.