Re: Co-location?
2000-04-25 16:09:07
At 03:48 PM 4/25/2000 -0400, you wrote:
>Hi:
>I'm puzzled. We have a storage pool with co-location set on, yet after
querying the volume usage table it suggest more than one node is stored on
a given volume. Anyone hazard a guess as to why?
Hi Larry,
Collocation does not guarantee that only one node will be stored per
volume. For example, if you have more nodes than volumes, then ADSM will
have to put multiple nodes on a volume. What collocation does is to strive
to collocate data from one node on as few volumes as possible. This is
implemented during migration, reclamation, and move data. When an output
volume is selected by one of these processes, it will preferrentially
select a volume that already has data from that node on it.
If you happen to have more tapes than nodes, and no node fills more than
one tape, then you will only see 1 node per tape.
..Paul
--
Paul Zarnowski Ph: 607-255-4757
Paul Zarnowski Ph: 607-255-4757
747 Rhodes Hall, Cornell University Fx: 607-255-8521
Ithaca, NY 14853-3801 Em: psz1 AT cornell DOT edu
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