DISKMAP reads the VTOC for one or more DASD volumes specified and produces a report that includes detailed allocation information for each dataset on the selected volume(s) followed by an allocation report showing what tracks on the volume are allocated to each dataset.

From the comments at the top of the source, DISKMAP originated at Triangle Universities and has had extensions/modifications at several installations, the last being AFDSC/SFI (Pentagon) in 1982.  There are a couple of versions on the CBT tape, one on the base tape at file #316 and another on the overflow tape at file #131.  The two versions are identical.

There were no modifications required in order to assemble DISKMAP under MVS 3.8j.  I did take the few minutes required to update the code that extracts/formats the system date for the heading to make it compliant for post-2000 dates.  While I was there I relocated that code from the heading routine so that it wasn't executed each time the page heading was produced.  



The jobstream to assemble DISKMAP - diskmap$.jcl - and execute the program - diskmap.jcl - are both contained in the archive:  diskmap.tgz [MD5: EBFF2710694C8B56376573BB65E749E3].  Download the archive and extract the contents (WinZip on Windows/?? or tar on Linux).  Submit the jobstream to assemble and link DISKMAP into SYS2.LINKLIB.  If you don't have SYS2.LINKLIB defined, you will need to modify the jobstream to specify a target load library.  Note:  The target library must be authorized.


Executing DISKMAP

DISKMAP requires no control cards or parameter options.  SYSUT1 must point to an actual dataset; it is not opened, but is used as a model to extract information about the datasets on the selected volumes.  The volumes to be analyzed should be indicated by one or more DDs following SYSUT1; each should specify the entire volume with a DISP=OLD.  The basic JCL is:

//             CLASS=A,MSGCLASS=A
//DD1      DD  DISP=OLD,UNIT=3350,VOL=SER=PUB001

The output from the jobstream above on my system may be viewed at:  DISKMAP output.

I hope that you have found my instructions useful.  If you have questions that I can answer to help expand upon my explanations and examples shown here, please don't hesitate to send them to me:

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This page was last updated on January 17, 2015 .