P9000Watch and P9000Sketch Reference guide for HP StorageWorks P9000 Performance Advisor v5.3 (T1789-96325, August 2011)

D Comparing LDEV response time metrics
in P9000 Performance Advisor and
P9000Watch
Maximum values of LDEV response time in P9000 Performance
Advisor and P9000Watch
The maximum values of LDEV response time in P9000 Performance Advisor cannot be compared with
the response time values in P9000Watch because P9000 Performance Advisor displays the I/O
response time as separate metrics for read and write, respectively.
P9000 Performance Advisor also displays the maximum and average values for LDEV response time
for reads and writes separately. The maximum values of the read and write response are displayed
within an interval of 30 seconds.
However, P9000Watch does not display any related metric for the maximum value of read or write
response.
Average values of LDEV response time in P9000 Performance
Advisor and P9000Watch
You can calculate the Average Read Response time and Average Write Response time using the
following formulae:
Average read response time
Front–end read response time over the collection interval / total front–end reads
Average write response time
Front-end write response time over the collection interval / total front–end writes
Because P9000Watch displays the cumulative LDEV response time (that is, both reads and writes
combined) a direct comparison of the average values of LDEV response time in P9000 Performance
Advisor and P9000Watch is not allowed.
P9000Watch and P9000Sketch Reference Guide 77