Specifications

Chapter 1. General usage 9
enabled. Only one restore version is possible for changed volumes. That is, multiple
concurrent generations of versions are not possible.
The commands associated with CKD versioning are:
$ alcckd /z/WORK01 -ve enable versioning for the indicated volume
$ alcckd /z/WORK01 -vr restore volume to original content
$ alcckd /z/WORK01 -vc commit the changes to the volume
$ alcckd /z/WORK01 -vi inquire about the versioning status of the volume
$ alcckd /z/WORK01 -vd disable versioning (if no changes have been made)
These examples use an emulated volume stored in /z/WORK01. You would specify the name
of the Linux file containing your volume, of course.
When changes are made to a track of a version-enabled volume, the original track contents
are saved at the end of the emulated volume file. Only one “original track” is saved;
subsequent changes to the track simply update the track within the emulated volume. If the
volume is restored, the original track(s) replace the changed track(s). If the changes are
committed, the original tracks are discarded.
Restoring or committing a volume results in a volume that is not enabled for versioning. It can
be enabled again with the -ve option.
The version-enabled status of a volume is carried over subsequent zPDT starts and stops,
and subsequent operating system IPLs. The version-enabled status remains until the volume
is restored or committed. The Linux file size for the emulated volume grows as additional
“original tracks” are stored. In an extreme case, where every track on the volume is changed,
the Linux file will grow to twice its original size. In typical cases, relatively few tracks on a
volume are changed through normal usage and the Linux file growth is minor. Restoring or
committing changes causes the Linux file to return to its original size.
If versioning has been enabled for a volume, but there have been no changes to the volume,
then the -vd option can be used to disable versioning. If there have been changes to the
volume (causing the versioning function to start operation) then the -vd option is rejected. At
this point you must use -vr (to restore the volume to the original state) or -vc (to commit the
changes) to disable the versioning function.
The -vi (inquiry) option displays the current versioning state of the volume and, if versioning is
active, displays the number of CKD tracks that have been versioned.
1.8 1090 messages
Messages issued by zPDT have unique message numbers. The msgInfo command can be
used to obtain more information about a message. An example of usage might be as follows:
$ awsckmap aprof1 (check my devmap)
AWSCHK200I Checking DEVMAP file 'aprof9' ...
AWSCHK204I Processed 204 records from DEVMAP /home/ibmsys1/aprof1
AWSCHK208I Check complete, 0 errors, 0 warnings detected.
$ msgInfo AWSCHK208I
AWSINF010I Format:
AWSINF013I AWSCHK208I Check complete, %d error%s, %d warnings detected.
AWSINF013I
AWSINF011I Description:
AWSINF013I The DEVMAP check is complete.