Ed, If the dataset is actually empty then it will not release space. From z/OS 1.11 a DSORG=PS dataset has a file mark written at the start of the dataset, which will allow DFSMShsm or DFSMSdss to release the unused space. This happens for SMS and non-SMS managed datasets.
I think this has been true for SMS managed datasets for a quite some time, but I forget when it was introduced. My experience is that it is rare to have a dataset without a DSORG assigned. Many shops will ensure a DSORG is assigned so that SDB works correctly. My experience is that DFSMShsm is very effective at releasing space from datasets that do not use Space Release Immediate in the Management Class, or use RLSE incorrectly in JCL. Ron > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of > Ed Gould > Sent: Friday, November 04, 2011 9:51 PM > To: [email protected] > Subject: Re: [IBM-MAIN] DSN NOT RELEASING OVER ALLOCATED SPACE > > Ron, > > It doesn't happen (at least in my experience). We ran a release space twice > daily on most of our DASD and got back 1000 cylinders or so twice a day. We > also had to explicit state on another release that we wanted to release any > space that did not have a dsorg in it. > > Ed > > > ----- Original Message ----- > From: Ron Hawkins <[email protected]> > To: [email protected] > Cc: > Sent: Friday, November 4, 2011 9:54 PM > Subject: Re: DSN NOT RELEASING OVER ALLOCATED SPACE > > How about just waiting for DFSMShsm to release it. > > > -----Original Message----- > > From: IBM Mainframe Discussion List [mailto:[email protected]] On > Behalf Of > > Steve Thompson > > Sent: Friday, November 04, 2011 11:07 AM > > To: [email protected] > > Subject: Re: [IBM-MAIN] DSN NOT RELEASING OVER ALLOCATED SPACE > > > > Willie: > > > > How about doing the following: > > > > //IDCAMS EXEC PGM=IDCAMS > > //SYSPRINT DD SYSOUT=* > > //SYSUT1 DD DUMMY > > //SYSUT2 DD DSN=PROD.OTKT.SORTED.PAYMT(+1),DISP=MOD, > > // SPACE=(TRK,1,RLSE) > > //SYSUT3 DD DSN=PROD.$$$$.SORTED.PAYMT(+1),DISP=MOD, > > // SPACE=(TRK,1,RLSE) > > //SYSIN DD * > > REPRO IFILE(SYSUT1) OFILE(SYSUT2) > > REPRO IFILE(SYSUT1) OFILE(SYSUT3) > > /* > > > > The SYSUT2/3 data sets will be opened for output. Nothing will be written > > because the SYSUT1 is dummy and gets an immediate EOD. The dealloc logic > > will then release the unused space. > > > > Regards, > > Steve Thompson > > Staff Software Engineer > > Connect:Direct for z/OS > > IBM - Software Group > > (469) 524-2622 > > [email protected] > > > > > > __________________ > > > > Lizette, > > > > Here is the jcl : > > > > DSN=PROD.OTKT.SORTED.PAYMT(+1),DISP=(,CATLG,DELETE),SPACE=(CYL,(800,200), > > RLSE),DCB=(MODELDCB,RECFM=FB,LRECL=740,DSORG=PS) > > > > > > > > > > ________________________________ > > From: Lizette Koehler <[email protected]> > > To: [email protected] > > Sent: Friday, November 4, 2011 10:12:54 AM > > Subject: Re: DSN NOT RELEASING OVER ALLOCATED SPACE > > > > > > > >Good Day To All, > > > > > >We are trying to figure out this problem. Job A executes, it creates > > several dsns and many of these dsns are empty. We have the RLSE parm > > coded however it doesn't seem release the unused space for the empty > > dsns. Is there a way of fixing this problem or a work around? We are > > running RELEASE z/OS 01.11.00 > > > > > >Thanks for your help in advance. > > > > > > > > > > > It would help if could you provid a screen show of 3.4 INFO for a dataset > > where the space did not release as well as the JCL statement and Jes > > messages for that dataset? > > > > > > > > Lizette > > > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access instructions, > > send email to [email protected] with the message: GET IBM-MAIN INFO > > Search the archives at http://bama.ua.edu/archives/ibm-main.html > > > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access instructions, > > send email to [email protected] with the message: GET IBM-MAIN INFO > > Search the archives at http://bama.ua.edu/archives/ibm-main.html > > > > > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access instructions, > > send email to [email protected] with the message: GET IBM-MAIN INFO > > Search the archives at http://bama.ua.edu/archives/ibm-main.html > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: GET IBM-MAIN INFO > Search the archives at http://bama.ua.edu/archives/ibm-main.html > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: GET IBM-MAIN INFO > Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
