StorageTek 6 manual Activities Report, •LSM operating statistics record, subtype 1, and

Activities Report

7.As the HSC attempts to float dismounts to a nearby LSM, there should be less pass-thru activity on dismounts than on mounts. However, to float cartridges, free cells must be available. Ejects also may incur more pass-thru activity than enters because the HSC attempts to place entered cartridges into the same LSM as the entry CAP. Ejected cartridges may take numerous pass-thru operations to move from their home cell to the preferred CAP.

8.The Activities Report summarizes information contained in SMF input. Two types of SMF records are written every HSC SMF interval:

•LSM operating statistics record, (subtype 1), and

•LMU statistics buffer data block records (subtype 4).

The Move section of the Activities Report only processes the LSM operating statistics records. LSM operating statistic records contain information describing moves which complete during an HSC SMF interval. When attempting to understand ACS performance it may be worthwhile to decrease the HSC SMF interval so the HSC SMF records describe finer intervals of time (see ‘‘Adding SMF Parameters’’ HSC Installation Guide).

For the ACS section of the Activities Report, output is based on an LMU interval. In a single host environment, the LMU interval is equivalent to the customer-defined HSC SMF interval.

In a multi-host environment, the LMU interval for each host is equivalent to the customer-defined HSC SMF interval for the host on which the HSC is running. In this case, data from all hosts must be combined to get an accurate picture of HSC activity. Combining data is necessary because the LMU’s reports of robotic motions and temporary error counts are not separated by the requesting host. Robotic motions and temporary error counts attributed to all hosts are combined and sent to the host that is currently requesting ACS statistics.

In addition, in a multi-host environment, cartridge motions initiated for one host may be accounted for in another host’s SMF data, depending on the relative length and timing of the SMF reporting intervals on the various hosts. This is true for data that appears in PM2 and CA-9 Reliability Plus (R+) reports, as well as in this report. The SMF subtype 7 records generated for each motion request are reported only by the host that initiated the request.

Note: For this report and for the CA-9 (R+) report, it is better to combine data from multiple hosts prior to generating the report so that the data from all sources will be reported and the totals and averages listed will be as accurate as possible.

194VM/HSC 6.0 System Programmer’s Guide

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