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5-12 Performance Monitor Operations
Hitachi Universal Storage Platform V/VM Hitachi Performance Manager User’s Guide
Note:
• It is possible that the sum of the usage rate for each volume in a parity
group is not equal to the usage rate for that parity group (see Viewing
Usage Statistics on Volumes in Parity Groups). This is because the
Performance Management window rounds off fractions below the decimal
point to the nearest whole number when
displayin
g
the usa
g
e rate for each
volume.
• If the CU is not the monitoring target, all items in the row are displayed in
italics. If you want to monitor those items, specify the CU as the
monitoring target by using the Monitoring Option window.
The list displays the following items:
• : When the green checkmark icon is displayed on the left of a volume,
the graph illustrates changes in usage rate for the volume.
• LDEV: This column indicates volumes (LDEVs), in this format: LDKC:CU:LDEV.
• Emulation: This column indicates device emulation types. • Usage: – The Ave. (Total) column displays the average usage rate in the
specified period.
– The Max. column displays the maximum usage rate in the specified
period.
• Read Rate:
– The Rnd. column indicates random read rates. A random read rate is
the ratio of random read requests to read and write requests.
– The Seq. column indicates sequential read rates. A sequential read rate
is the ratio of sequential read requests to read and write requests.
• Write Rate:
– The Rnd. column indicates random write rates. A random write rate is
the ratio of random write requests to read and write requests.
– The Seq. column indicates sequential write rates. A sequential write
rate is the ratio of sequential write requests to read and write requests.
• Parity Gr. Use[Exp]: This item is displayed only when you select
longrange for the storing period of statistics. Parity Gr. Use[Exp]
assumes the volume might be migrated out of the parity group (or
uninstalled) and indicates expected (estimated) average and maximum
usage rates of the parity group. The Ave. (Total) column indicates an
estimated change in the average usage rate. The Max. column indicates an
estimated change in the maximum usage rate.