There are two types of MAR programs:
- Disk configuration acquisition program
This program scans a storage system to acquire disk configuration information. The disk configuration information is used to determine the correspondence between recognition names in the host (device numbers, VOLSER, and SMS storage group names) and device addresses (control units and command control addresses).
You must scan the following volumes to acquire disk configuration information.
- Volumes from which LDEV performance information is to be collected
- I/O destination devices
- Metric collection program
This program runs as a started task and collects metric performance information. The metric collection program collects performance information from a storage system at the specified metric collection interval and then stores the information in the SMF dataset in the SMF record format.
The following figure provides an overview of performance information collection by the metric collection program.