Warning!  This is not a supported configuration.  Currently, the
official position is that the drives need to be dedicated to a
particular server.  The 3494 does not have any problem being
accessed by multiple servers.  And physically, the 3590 drives can
be attached to multiple systems...but they can not be shared by
multiple systems with impunity.  The problem is that an underlying
RESERVE macro does not currently operate  across systems.  Thus,
an adsm server can not be sure it has exclusive rights to a drive.
You can run like this but you open the door for problems..eg, one
adsm server is using one of its tapes and the other server requests
a scratch mount...the tape in the drive will look like a valid
scratch tape to the second server.

ADSM did recently put in an enhancement to allow dynamic sharing of
3590 drives within a 3494...but only for sharing between ADSM and other
applications on the same system (including a 2nd adsm server on the
same system).  This support is not for across system.

I would encourage those interested to open a 3590 requirement for this.
...greg tevis

================================================================
 I realize that this isn't strictly an ADSM question, but I know
 there are many people on this list with 3494 tape libraries and
 3590 drives. We currently have a 3494 with six 3590 drives in it.
 Three of the 3590s are hooked up to one ADSM server, and the
 other three are hooked up to another ADSM server (both of which
 are SP2 wide nodes).

 I'm wondering if, b/c the 3590s are twin-tailed, I can hook all
 six 3590s to each of the two ADSM servers without causing any
 conflicts. Since tape requests and such go through the library
 manager control point, would there be any contention for the
 drives that would cause problems? I realize there will be
 contention, but I'm thinking that the 3494 will arbitrate things,
 and at any given point a single ADSM server could have access to
 all six drives, assuming none are being used by the other server.