> IBM did away with that a LONG time ago on MVS. My memory is bad on dates but > I would guess in the late 80's (??). ANyone?
I'm not sure to what your "that" refers. IBM began releasing the initial pieces of what turned into SMS (System Managed Storage) in the late 1980s, but I don't see anything in the poster's text that refers to any problem for which SMS was the solution. IBM did away with DOS/360's lack of free space management in OS/360 in the mid-1960s by supporting the Format 5 DSCB in DADSM for the management of free space on DASD. The system (OS/360) had been managing storage for 20+ years before IBM began designing SMS, which did not suddenly begin managing free space but rather was intended to make it easier for users to create new data sets by removing the necessity for users to supply so many different JCL keywords. Bill Fairchild Software Developer Rocket Software 275 Grove Street * Newton, MA 02466-2272 * USA Tel: +1.617.614.4503 * Mobile: +1.508.341.1715 Email: bi...@mainstar.com Web: www.rocketsoftware.com -----Original Message----- From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf Of Ed Gould Sent: Saturday, February 27, 2010 5:03 PM To: IBM-MAIN@bama.ua.edu Subject: Re: Item on TPF ________________________________ From: Charles Mills <charl...@mcn.org> To: IBM-MAIN@bama.ua.edu Sent: Sat, February 27, 2010 10:56:03 AM Subject: Re: Item on TPF VSE does not support the Format-? (3? 5?) VTOC record that inventories free space. "Traditional" DASD space management in VSE involves a chart on the sysprog's wall showing which tracks of each volume are free. All "traditional" DASD space allocation in VSE is what z/OS JCL calls ABSTR (is that the right spelling?). A backstop against "oops" is that VSE datasets are usually defined with an expiration date (unlike z/OS) which causes VSE to complain if one attempts to overwrite them. The more modern approach in VSE uses large VSAM extents as "sub-regions" of a disk. VSAM then allocates space for sequential datasets within this area. I think there are also some third-party solutions. I know I set out to write one once (but did not complete the project). Charles Charles: Really?? how curious IBM did away with that a LONG time ago on MVS. My memory is bad on dates but I would guess in the late 80's (??). ANyone? Ed ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
