Craig and all,
We are running here, -with V2 servers- in an environment where 4 ADSM servers,
running on 3 platforms, are sharing tape drives connected to 2 3494.
Not all tape drives are seen by all platforms, but all tape drives are seen by
at least two of them.
We do this by defining a drive to only one adsm server at any given time,
therefore relying on "human" interlock to avoid several servers attempting
access to the same drive at the same drive.
It works well as long as one does not have to move drives from server to server
on a regular basis. However, re-allocating drives can be an unnerving
experience. The most difficult part is to remove a drive from a server. As our
tape drives are always busy, the only practical way to do so is to disable
access to the server, reduce the mount retention to one minute, wait for the
requested drive to become available, reduce the mount limit, provided that the
server allows it, delete the drive, and re-enable access. This can take a long
time... My understanding is that V3 servers are providing tools that should
allow to ease this processing, though.
An alternative mechanism that I am surprised nobody mentionned yet is to use
NETTAPE, IBM GA-product that is allowing dynamic sharing of tape drives between
many applications, such as (but not restricted to) ADSM servers. Granted, it is
still suffering from youth problems, but we have seen tremendous improvements
being done to it in the last three months, to the extend that we are planning
to put it in production in the next couple of months.
--
Regards
Regards
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