Sun Microsystems StorageTek Modular Library System SL500 - Manual (Page 170)

Capacity on Demand Features and Restrictions
138 SL500 User’s Guide • July 2008 Revision: KA • 96116
■
Storage capacity is incremental. Total licensed capacity is equal to the sum of the
capacities specified in each license key file installed and activated on the library.
■
The order that capacity licenses are installed is not significant (that is, it does not
need to match the order of the modules in the SL500 frame).
Terminology
The following terms are used to describe library capacity management:
■
Physical or installed capacity—The number of storage cells physically present in the
library.
■
Licensed capacity—The number of storage cells the library is licensed to use. This
cannot exceed the installed capacity.
Planning Library Capacity
The SL500 does not support gaps in licensed capacity; all storage cells must be
contiguous. This has the following effects on capacity planning.
You can begin adding licensed capacity to a module only if the module directly above
it is licensed at full capacity.
Deleting a Capacity license for a module in the middle of a library will cause the
modules below it to be unavailable.
Note – CEMs must be at the bottom of any SL500 configuration. A CEM cannot be
installed between a Base Module and a DEM.
Example: Base Module + DEM
The Base Module must be licensed at full capacity before you can begin
adding licensed capacity to the DEM.
Example: Base Module + DEM + CEM + CEM
Removing any portion of the DEM capacity will make both CEMs
unavailable.