On Tue, May 3, 2016 at 10:54 AM, michelbutz <michealb...@comcast.net> wrote:
> I am sorry dont understand what is the VTOC > Dataset name, there is another dataset on that volume sys1.vvds.v > concentrated to the volser > SYS1.VTOCIX.aaaaaa (aaaaaa is _normally_ the same as the volser, but need not necessarily be) is a _index_ into the actual VTOC itself. It does not contain the VTOC information. SYS1.VVDS.Vaaaaaa (aaaaaa, again, is _normally_ the same as the volser, but need not necessarily be) is a VSAM-like data set which contains SMS information for data sets in the VTOC. The VTOC is the Volume Table Of Contents. IT IS NOT A DATA SET!!! It does _not_ show up in a VTOC listing of data sets on a volume. The VOL1 record on a volume contains a field which points to where the VTOC exists. The VTOC is "self described" in the type 4 VTOC record. The VTOC most closely resembles a keyed BDAM data set (remember, it's not a data set!) which has a 44 byte hardware key. The hardware key is the same as the DSN. For the VTOC, the hardware key is 44x'04', that is 44 repetitions of the hex value x'04'. When z/OS processes the VARY ONLINE command for a DASD device, it reads the VOL1 record. This validates the volume serial is unique and it then stores the address of the VTOC in the UCB for other users, such as DADSM allocation. I don't know what you want to do, but personally, I prefer using the output from the IDCAMS DCOLLECT command for data set information. Of course, it is not useful for a "one off" data set requirement. If you want a VTOC mapping of where data sets reside on a volume, for some reason, then using ADRDSSU with a PARM='TYPRUN=NORUN' and a DEFRAG command will get you a fairly nice listing. You could also do a IEHLIST of the volume. Oh, and I also use the REXX / TSO LISTDSI command for data set information retrieval. -- The unfacts, did we have them, are too imprecisely few to warrant our certitude. Maranatha! <>< John McKown ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
