If all the PDSE directory blocks are full it grabs another block for the directory, it can't run out of space unless the entire data set cannot be expanded.
On Thu, Oct 22, 2020 at 5:30 PM Joel C. Ewing <jce.ebe...@cox.net> wrote: > > I would assume a directory entry must be created before attempting to > allocate space for the contents of a new PDSE member. So, assuming the > PDSE has no free blocks and cannot be extended, do you get a different > type of ABEND if the out-of-space condition occurs at directory entry > creation time because a new directory block just happens to be needed vs > finding space in an existing directory block and then hitting the > out-of-space condition trying to allocate a block for the member data? > With no free blocks, obviously no new members can be added to the PDSE, > but it looks like it might still be possible that the failure could be > reflected differently to the user or program depending on purpose for > which a block were needed at the initial point of failure. > > In a pathological case where you were just adding a very large number > of Alias directory entries pointing to existing members, I would think > you could use all remaining free blocks in the PDSE just for directory > blocks without allocating any new blocks for member content, so if PDSE > block allocation failure makes any distinction between failures > occurring when a directory block is needed vs a member data block, that > would be another case that might be reflected as a shortage of directory > space. > JC Ewing > > On 10/22/20 10:52 AM, Charles Mills wrote: > > Putting it differently, there is no distinction between "member data space" > > and "directory entry space." Being out of one is being out of both. A PDSE > > of 10 tracks could equally well hold one member of ~500K or lots and lots > > of tiny or "null" members. A mischievous programmer adding an unbounded > > number of empty members would be no different in effect from a mischievous > > programmer adding one member of unbounded size. > > > > Charles > > > > > > -----Original Message----- > > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On > > Behalf Of R.S. > > Sent: Thursday, October 22, 2020 7:29 AM > > To: IBM-MAIN@LISTSERV.UA.EDU > > Subject: Re: emptying a PDS: was RE: [IBM-MAIN] getting XCFAS down > > > > W dniu 22.10.2020 o 15:12, Paul Gilmartin pisze: > >> On Thu, 22 Oct 2020 13:50:44 +0200, R.S. wrote: > >> > >>> Remark: while shortage of space is possible in PDSE, then shortage of > >>> directory blocks is not possible. > >>> > >> What happens if an inquisitive programmer mischievously adds an > >> unbounded number of empty members to a small PDSE? Or adds > >> numerous aliases to a nearly full PDSE? > > My guess: x37 abend or next extent. This is NOT directory full, it is > > lack of space. > > > > ... > > > -- > Joel C. Ewing > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN -- Mike A Schwab, Springfield IL USA Where do Forest Rangers go to get away from it all? ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
