Staller, Allan wrote: <snip> It sounds like you are not using Dynamic Volume Count or Partial Space release.
Dynamic volume count allocates the 1st extent on the 1st volume and dynamically adds volumes to the list, up to the architectural max of 59. It is not necessary to specify (for example) 10 volumes in JCL. It is specified in the DATACLAS assigned to the dataset. Partial Space Release will release unused space with a sequential file at dfHSM Primary Space Management time. This is specified in the MGMTCLAS assigned to the dataset. </snip> Thank you. I had had a look in DFSMS doc, but I didn't pay (enough) attention to the Dynamic Volume Count, I'll do so now. As to partial space release, it says right there in the doc: <snip> For a multivolume data set that is not in extended format, or is in extended format with a stripe count of 1, CLOSE releases space only on the current volume. </snip> This is exactly what I see in my testing. As to the Guaranteed Space in the STORCLASS, I also avoid it since it says in the doc that partial space release is incompatible with it. Thanks anyway for the quick reply. <snip> I have an application that may have to write DASD files very variable in size. These files are dynamically allocated as SMS managed files (using DALSTCL, DALMGCL and DALDACL) and with text unit DALRLSE (equivalent of the RLSE JCL keyword) so that unused space is released from the allocation when closing the file after writing it. This works well with mono-volume data sets, but is it possible to make it work for multi-volume data sets too ?? After testing a bit, it looks like: - At the time of allocation , the primary space amount is allocated on EACH of the volumes if the volume count (DALVLCNT) is greater than 1. - At the time of CLOSE, the unused space is released on the current volume (the last one that was written to). But, and this is my problem, the allocations on the (unused) next volume(s) if any, are NOT freed !!! Is it possible to specify something (in SMS ?) so that it would free ALL unused space ? </snip> ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
