HP StorageWorks SAN Virtualization Services Platform Administrator Guide (5697-0934, May 2011)

The following table describes the available counters and what they measure.
ExplanationCounter name
Measures the average time it takes to complete a read for
a mirror job
Sync.Mirror Job Average Read Response Time (microSec)
Measures the average time it takes to complete a write for
a mirror job
Sync.Mirror Job Average Write Response Time (microSec)
Practical measurements with the VSM show that it behaves properly as long as the average write
response time to the setup volume does not exceed 20mSec (or 20000 micro seconds in the
Performance Monitor counter). When evaluating the access capabilities of a VSM to the setup
volume, it is recommended to start with the Sync.Mirror Group Average Write Response Time. If
this value is higher than expected, then check the performance of the individual jobs that construct
this mirror group, and try to find out if there is a particular job that is slower than others and
degrades the overall performance. In order to fix such an issue, you should break the slowest job
and re-create it on a faster (or less loaded) array.
The following image is an example of using Windows Performance Monitor to show the synchronous
mirror writes to the setup volume. The graph combines the overall performance of the synchronous
mirror group and the write performance of the individual jobs.
54 Monitoring the SVSP domain