If you read record 3, the volume label, it contains both the actual and logical (recomped) size of CMS-formatted minidisks (and other interesting stuff). See http://www.vm.ibm.com/pubs/cms440/ADTDSECT.HTML beginning at offset x'A0'
Mike Harding EDS VM National Capability 134 El Portal Place Clayton, Ca. USA 94517-1742 * phone: +01-925-672-4403 * Fax: +01-925-672-4403 * mailto:[EMAIL PROTECTED] * <mailto:[EMAIL PROTECTED]> (personal) Note: For 2005, I am off on Fridays with even Julian dates and Mondays with odd ones. -----Original Message----- From: VM/ESA and z/VM Discussions [mailto:[EMAIL PROTECTED] On Behalf Of Bill Stephens Sent: Friday, October 28, 2005 5:53 AM To: [email protected] Subject: Re: DASD map tool? Dave Kreuter wrote "I agree that a 1 cylinder scan is quite useful. I've used it myself. There are times though where a successful CMS access could be misleading. Any disk that was recomped such as the 190 will return incorrect results. It is also possible that a minidisk that has been deleted will still show up with its cylidner 1 intact potentially pointing at garbage. Just be aware of this and a DISCOVER tool is still quite effective.". This is quite correct. Usually, there will be a gap evident in the map file following the 190 disk, which +may+ give you a clue as to the correct size of the 190 mdisk (e.g., if in the directory, the 190 minidisk is immediately followed by another minidisk, then the ACCESS reported size plus the gap size is the true size). But that's only if there is no actual gap between 190 and the next minidisk in the directory. Another issue that DISCOVER can't detect is when disks get "overlaid". Consider: 1) user "A" has a minidisk allocated at cylinder 100 for 10 cylinders 2) user "B" has a minidisk allocated at cylinder 105 for 4 cylinders (never mind how or why) In this case, DISCOVER will report that there is a minidisk at cylinder 100 for 10 cylinders, and another minidisk at cylinder 105 for 4 cylinders. That's why the best use of DISCOVER is in conjunction with IEBIBALL. Regards, Bill Stephens Sr. Technology Analyst, High Availability SunGard Availability Services 10th floor 401 North Broad Street Philadelphia, PA 19108 Phone: (215) 351-1099 Fax: (215) 451-2045 [EMAIL PROTECTED]
