--- Received from VD.LD  +46-(0)31-667479           95-10-19 13:31
  -> IN=adsm-l(a)vm.marist.edu
  -> IN=adsm-l(a)vm.marist.edu

Please, look at this tape mount problem an tell me what I'm
doing wrong.

Installation.
  We serve ca 140 file servers. 100 of them are OS/2 servers with
  6 GB each. The sum of "q occ" is 530 GB. The amount of
  incremental backups per 24 hours is 6 GB (avg.). Database is 7,5
  GB (95% used). Server on MVS. All copy groups pointing to a DASD
  stg of 2,5 GB.

Migration.
  Migrprocess is set to 1 (default - allow only one migration
  process in parallel). Mount limit is 3 (max. number of tapes
  mounted in parallel). Maximum size threshold is 900 MB (should
  not generate any extra tape mount). Next stgpool is a tape
  stgpool with collocate off.

Problem.
  When the migration runs, in parallel with a lot of backup
  sessions, suddenly two more tapes are mounted, used some seconds
  only and then kept. These two (maximized by mount limit) tapes
  keeps on coming up and down independent of each other a lot of
  times during the migration. Afterwards, we can see that such a
  tape keeps several node file clusters from previous "normal"
  migrations and last are some single files mixed from different
  nodes. I.e. the last mixed files shows that the tape has been
  used a lot of times to migrate, or backup, only one small file
  each time. Even if we have a tape library, these tape mount are
  very much unneeded.

  What initializes the tape mounts?

    Lars Danielsson, Volvo Data, Goteburg, Sweden.

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