Справочник Пользователя для Sun Microsystems SL8500

Library Complex

20 StreamLine™ SL8500 Modular Library System User's Guide • March 2007

Revision K • 96154

Pass-thru Ports 

A PTP is an electro-mechanical device that allows one Library Storage Module (LSM) to 

pass a cartridge to another library storage module within the same complex. 

For example: If an operating system issues a mount request, and all the tape drives are 

busy in that LSM and library, the PTP can pass the cartridge to another library where 

an idle tape drive can satisfy the mount request. 

There are eight PTP locations in an SL8500 library, two locations per rail (or LSM). 

These locations are on the curved portions of the Robotic Interface Module near the 

tape drives. Therefore, they provide quick access to the drives.

The SL8500 PTPs consist of a separate frame (

) that is installed between the 

Drive and Electronics Module and the Robotics Interface Module. Each frame has four 

separate PTP mechanisms that can pass up to two cartridges each between LSMs (one 

cartridge mechanism) for a total of eight cartridges. 

The maximum size of a library complex connected through PTPs is 7 libraries. 

Because elevators transfer cartridges from one LSM to another, these transfers 

are also pass-through operations. The elevators are thus internal PTPs, considered by 

host software to be on Panel 0. 

The following terms and definitions apply to SL8500 PTP operations: 

Pass-thru Port 

Home library

Provides power, signal, and control lines to the PTP mechanisms.  This is the 
library on the right as viewed from the front.  

Away library 

Always located on the left side of a Home library, as viewed from the front. 

Source

Contains the home slot location for the cartridge that will be passed through 
to an adjacent library. 

Destination 

Contains the tape drive or slot location in the adjacent library where the 
cartridge will be mounted or stored.