Should be able to do this anytime. I would pick a low-activity period just in case. IGDSMS00 points to the SCDS/ACDS/COMMDS that will be used at the next IPL. If IGDSMS00 is not updated to match the current dataset usage, there may be issues at the next IPL.
HTH, <snip> thx for your replies, this situation happens on a single image, so, according to your replies I think I can do it as follows: a) define a new ACDS: //STEP EXEC PGM=IDCAMS //SYSUDUMP DD SYSOUT=* //SYSPRINT DD SYSOUT=* //SYSIN DD * DEFINE CLUSTER(NAME(SMS.DESV.ACDS) - LINEAR - VOL(*) - CYL(75) SHAREOPTIONS(2,3)) - DATA(NAME(SMS.DESV.ACDS.D) REUSE) b) SETSMS SAVEACDS(SMS.DESV.ACDS) c) SETSMS ACDS(SMS.DESV.ACDS) PARMLIB/IGDSMS00 defs are ok. No need to change them. Is this disruptive ?? I never did such a thing. What happens to active jobs ?? Is it better to this out of busy period?? </snip> ---------------------------------------------------------------------- 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