StorageTek 6 manual Reduce Operator Intervention, Ensure adequate free cells, Set CAP Preference

Ensure adequate free cells

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.

Eject through the CAP closest to the cartridge

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.

Redistribute cartridges during off-peak times

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.

Reduce Operator Intervention

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:

Set CAP Preference

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.

424VM/HSC 6.0 System Programmer’s Guide

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