StorageTek Host Software Component 6 User Manual

1st ed., 6/30/04 - 312579601

Setting MNTD Float to ON can be defeated if there are no free cells in the 
dismounting LSM. Dismounted cartridges are passed to other LSMs to find a new 
home cell.

Use the Display Lsm command to determine the number of free cells in each LSM. 
Use MOVe or EJect to create free cells if they are needed. 

If you eject a cartridge through the CAP of the LSM where it resides, no pass-thrus 
are required. 

If you eject a cartridge without specifying a CAPid, the cartridge is ejected through 
the highest priority CAP that is not busy. This type of activity may cause one or more 
unnecessary, nonproductive pass-thrus. 

The recommended way to accomplish ejects without affecting performance with 
pass-thrus, is to use multiple CAP option on the EJECt utility. By specifying multiple 
CAPs (that is, CAP(000,001,002)), the desired effect (that is, no pass-thrus) is 
achieved. 

You can use the MOVe command and utility to move cartridges within an LSM or 
between LSMs. The Scratch Redistribution utility can be used to move scratch 
cartridges between LSMs until an equilibrium is reached. Each inter-LSM movement 
of cartridges causes pass-thrus which delay robot movement in mounting a cartridge. 

Depending on the number of cartridges to be redistributed, you may prefer to 
schedule moves and scratch redistribution during periods of low data center activity. 
The redistribution runs faster and performance is not affected during off peak times.

Although the ACS runs mostly unattended, situations occur where operator intervention is 
required. Excessive and unnecessary operator intervention impacts library performance. 
There are specific ways in which operator intervention can be reduced. These include:

In a multiple-LSM ACS, the CAPPref command establishes an ordered list of CAPs 
to use should the operator or HSC start an activity that requires a CAP without 
specifying a CAPid. 

To motivate operators to enter or eject cartridges faster, set CAPPref such that the 
CAP closest to the cartridge racks is preferred. This minimizes operator travel 
distance. 

In large ACS configurations, of five or more LSMs, consider setting CAPPref such 
that a CAP in the middle of the ACS has the highest priority. This may make the 
operators walk further, but it reduces the number of pass-thrus should the default 
(highest priority) CAPid be used for ejecting cartridges.