Hitachi MK-96RD617-08 - Manual (Page 28)

2-12 About Performance Manager Options
Hitachi Universal Storage Platform V/VM Hitachi Performance Manager User’s Guide
Apart from the items listed above, Performance Monitor also displays
additional information about hard disk drive workloads. For details on how to
view workload statistics about hard disk drives, see Monitoring Hard Disk
Drives.
Port Traffic Statistics
Performance Monitor tracks host ports and storage system ports to obtain
statistics about I/O rates and transfer rates at these ports. If you analyze
these I/O rates and transfer rates, you can determine which hosts issue a lot
of I/O requests to the disk and which hosts transfer a lot of data to the disk.
For details on how to view statistics about traffic at ports, see Monitoring
Ports.
You will be unable to view workload statistics that expired a specific storing
period because such statistics are erased from the storage system. The storing
period of statistics is only short range (between 8 hours to 15 days) and that
changes depending on the collecting interval specified by the user. For details
on the storing period of statistics, see Understanding Statistical Storage
Ranges.
Important: Performance Monitor can obtain statistics about traffics of ports
connected to open-system host groups only. The statistics about traffics of
ports connected to mainframe host groups cannot be obtained.
LU Paths Traffic Statistics
Performance Monitor tracks LU paths to obtain statistics about I/O rates and
transfer rates at these LU paths. If you analyze these I/O rates and transfer
rates, you can detect LU paths though which a lot of I/O requests are made to
the disk. You can also determine the LU paths through which a lot of data are
transferred to the disk. For details on how to view workload statistics about LU
paths, see Monitoring LU Paths.
You will be unable to view workload statistics that expired a specific storing
period because such statistics are erased from the storage system. The storing
period of statistics is only short range (between 8 hours to 15 days) and that
changes depending on the collecting interval specified by the user. For details
on the storing period of statistics, see Understanding Statistical Storage
Ranges.
The traffic statistics reported for an LU is aggregated across all LU paths
defined for an LU.
• I/O rate is the sum of I/Os across all LU paths defined for an LU.
• Transfer rate is the total transfer rate across all LU paths defined for an LU.
• Response Time is the average response time across all LU paths defined
for an LU.