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Viewing Workload Statistics on LU Paths
When you select LUN (
then select Detail, the graph displays detailed statistics about workload on the
LU paths. The detailed statistics that can be displayed differ depending on
items you select in the list, as explained in Table 4-3.
Table 4-3
Select Detail and this Item in the
IO (the number of I/Os per
second)*
Read (the number of read accesses
per second)*
Write (the number of write
accesses per second)*
Read Hit (the read hit ratio)
Write Hit (the write hit ratio)
Back Trans. (backend transfer; the
number of I/Os between the cache
memory and hard disk drives)
* You can select this item only when I/O rates are displayed.
4-20
Hitachi Universal Storage Platform V/VM Hitachi Performance Manager User's Guide
) in the tree, select a LUN in the list, click Draw, and
Detailed Information that can be Displayed in the Graph (Port-
LUN Tab)
List
- statistics in sequential access mode
- statistics in random access mode
random access mode is used for transferring data instead
of sequential access mode. For example, random access
mode is likely to be used for transferring data to disk areas
to which the Cache Residency Manager function is applied.
- the number of data transfers from the cache memory to
hard disk drives ("Cache to Drive")
- the number of data transfers from hard disk drives to the
cache memory in sequential access mode ("Drive to Cache
Seq.")
- the number of data transfers from hard disk drives to the
cache memory in random access mode ("Drive to Cache
Rnd.")
Using the Performance Manager GUI
The Graph Contains
Note: If the read hit ratio or the write hit ratio is high,
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