Siemens SM2 monitoring system Manuel D’Utilisation
U3585-J-Z125-8-76
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SM2 reports
PCA CACHE report
READ H-R. (%)
Percentage of hits based on the total number of read operations to
be executed as fast reads
be executed as fast reads
WRITE (1/S)
Total number of write operations (in I/Os per second)
FAST W. (1/S)
Total number of high-speed write operations (in I/Os per second)
C-OVER (1/S)
Number of unsuccessful attempts to use the cache due to a cache
overrun (in I/Os per second)
overrun (in I/Os per second)
Notes
If a miss occurs during a caching read operation ("fast read"), the data is read from disk
and (in contrast to a read operation) stored in the cache. Cache overruns can only occur
in write operations. In the event of an overrun, the write operation bypasses the cache
and is performed directly on the disk.
and (in contrast to a read operation) stored in the cache. Cache overruns can only occur
in write operations. In the event of an overrun, the write operation bypasses the cache
and is performed directly on the disk.