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