HP XP Array Manager Software User Manual
Page 65
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 about Parity Groups
This is because the Auto LUN window rounds off fractions below the decimal point to the nearest
whole number when displaying the usage rate for each volume.
•
If the CU is not the monitoring target, all items in the row are displayed in italics. To monitor those
items, you must 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). The number on the left of the first colon from the left
is the LDKC number. The number on the left of the second colon from the left is the CU image
number. The number on the right of the second colon is the LDEV number.
•
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.
For example, if the Ave. (Total) box for the volume 0:01 displays 20 -> 18, the average usage
rate of the parity group that the volume belongs to is 20 percent. If the volume were migrated out
of the parity group, the average usage rate of that group is expected to drop to 18 percent.
•
Business Copy: This item is displayed only when you select shortrange for the storing period of
statistics. Business Copy indicates the percentage of the processing of the following programs to
all the processing of the physical drives, for each volume. This value is found by dividing access
time to physical drives by the following programs by all the access time to physical drives.
• ShadowImage for Mainframe
• XP Business Copy
• HP StorageWorks XP for FlashCopy Mirroring Software
• HP StorageWorks XP for FlashCopy Mirroring V2 Software
XP24000/XP20000 Performance Monitor User Guide
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