StorageTek 6 manual Define Secondary and Standby Control Data Sets

Define Secondary and Standby Control Data Sets

Various controls and services are in place in the HSC subsystem to ensure that the primary control data set maintains its integrity. Included among the controls are the capability to:

•designate secondary and standby control data sets as backup

•run BACKup and RESTore utilities

•designate journal data sets for use in recovery of control data set errors.

However, though all of these means are available, you must configure your installation to take advantage of the capabilities. At installation, when defining the library configuration, it is important that you initialize the additional control data sets.

It is highly recommended that secondary and standby data sets be used to ensure the performance and reliability of your library.

Refer to Chapter 7, ‘‘Allocating and Initializing Control Data Sets’’ in the HSC Installation Guide for information about defining control data set requirements at HSC installation.

The HSC Operator’s Guide contains information about the operator commands to control switching of control data sets.

Limit View Time to Maintain High Performance

Certain conditions within a library can significantly affect performance. These conditions may occur because of software issues or simply because of daily procedures used within a data center. The VIew command is invoked to improve performance because it can be used to quickly resolve problems. It can often eliminate the need for an operator to open an LSM door and enter the LSM to resolve a problem. Excessive use of the VIew command is a typical example of how library performance can be drastically affected unless you plan and consider how it can impact the performance of your library.

Note: The SL8500 library does not contain a camera, so the VIew command is not useful in that environment.

Though the VIew command is primarily used by operators, it is important for systems programmers to know that excessive use of the VIew command for extended periods of time can impact the performance of an LSM and your library. However, you should use the VIew command to inspect the interior of an LSM rather than place the LSM in manual mode and physically enter the LSM. If it is necessary to inspect the robot, its hands, and/or cameras, you must modify the LSM offline and enter through the access door.

Default view time can be controlled with the OPTion command’s Viewtime parameter. The system default for view time is 10 seconds. However, you can change this default value to fit your needs.

Refer to ‘‘Option Command and Control Statement’’ in Appendix A, ‘‘Macros, Control Statements, Utilities, and Commands Syntax Reference’’ or to Chapter 2 in the HSC Operator’s Guide for detailed information about the OPTion command’s syntax and parameters.

Chapter 6. Performance Considerations 419

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