Using MEDINF REPLACE commands to implement volume replacement policies

DFSMSrmm automatically works with the tape drive SARS MIM alerts to track volume errors and volumes that need replacement. In addition, built-in policies for IBM media are used to determine when volumes should be replaced. You can create your own customized replacement policies using the MEDINF REPLACE values based on media type. You can create your replacement policy by specifying one or more of the following MEDINF REPLACE values:

AGE: Use this operand when your policy is to be based on your known usage characteristics and the expected life of the technology, not the expected failure of the tape media.
Properly cared for magnetic media should have a life expectancy equal to or greater than that of the recording technology concerned. When you select Age as one of the criteria for replacement of media, you are really deciding based on your known usage characteristics and the expected life of the technology at what future time you plan to replace the technology, not the expected failure of the tape media. Many experts believe that you should recopy data every 10 to 20 years to ensure that you have the technology required to read the data when required. For further reading on this subject, see Care and Handling of Computer Magnetic Storage Media, by S. G. Geller, National Bureau of Standards Special Publication 500-101, for sale by the Superintendent of Documents, U. S. Government Printing Office, Washington, D.C. 20402.
PERM: Use this operand when your policy is to be based on permanent I/O errors. DFSMSrmm compares your value with the sum of permanent read and write errors over the life of the volume. PERM(1) is the default value.
TEMP: Use this operand when your policy is to be based on temporary i/o errors. DFSMSrmm compares your value with the sum of temporary read and write errors over the life of the volume.
WMC: Use this operand when your policy is to be based on how many times the volume is mounted for output and written to. DFSMSrmm compares your value with the write mount count for the volume.

Once policies are implemented, you can regularly report on volumes to be replaced. Volumes that have already expired, and have the REPLACE action, can either be replaced and the action confirmed, or they can be deleted. Volumes with the REPLACE release action should be considered as candidates for copying so that any bad media can be replaced. If the volume is owned by an application that tracks the volume serial number, such as DFSMShsm and OAM-owned tape volumes, you can use the built-in functions of that application to recycle, or move the data to a new volume. For all other data, you can use a product such as IBM Tivoli Tape Optimizer to copy data onto new volumes and recatalog the data, where necessary.

You can manually maintain the volumes to be replaced by disabling the built-in policy management provided by DFSMSrmm. To check for media errors, do one of the following:

Use reports based on the extract file with the DFSMSrmm report generator.
Use the EREP System Exception report.
Contact your IBM Service representative to check the Service Agent reports.

For volumes that need to be replaced, set the release action to REPLACE and allow DFSMSrmm to manage the replacement of the volume.

See Defining media information: MEDINF for information about defining media information.

These sample reports, shipped in the DFSMSrmm Report Generator, can help you identify the volumes to be replaced:

EDGGREPL - This sample report can help you identify the volumes that should be replaced. Volumes are selected for this report if the volume is pending release with the REPLACE action, or if the release action is set to REPLACE.
EDGGREPV - This sample report can help you define your own customizable Volume Replacement Policies. You can use the report to determine for which volumes you will manually set the REPLACE release action. The sample report is set up to select volumes if one or more of the following is detected:
- Write mount count > 99
- > 25 years old and > 50% used
- Temporary write errors > 20
- Permanent write errors > 1

Seez/OS DFSMSrmm Reporting for information about the DFSMSrmm Report Generator.