Measure Reference Manual

Counter TypeDescriptionSubfield
Snapshot(ZMS Style only) Number of cache blocks that were in use
at the end of the measurement or at measurement interval
BLOCKS-INUSE-END
copy time. When TOTALS ONLY or TOTALS INCLUDE is
used, this value is the total number of cache blocks in use
at the end of the measurement or at measurement interval
copy time.
Incrementing(ZMS Style only) Number of block splits (per block size)
for the volume.
BLOCK-SPLITS
IncrementingNumber of times a required block is found in cache on a
read or buffered write operation, which saves a disk I/O.
HITS
This counter includes cache hits on both read and write
operations.
IncrementingNumber of times a required block is not found in cache
on a read operation, which causes a disk I/O. Read
MISSES
operations that do not go through cache are not included
in this counter.
IncrementingNumber of times the cache tables indicate a required block
is in cache, but not because the memory manager is using
FAULTS
it for another purpose. Faults occur when a cache is too
large or physical memory is too small for a given
application. Fault rates greater than 5% of all I/O
operations generally indicate you need more memory.
IncrementingNumber of times the disk process had to write to the
audit-trail volume before it could write a dirty cache block
AUDIT-BUF-FORCES
and thereby free that block for another use. This value
should be close to zero.
QueueTime that cache blocks spent dirty. A cache block is dirty
when a buffered write operation writes data to it. After the
BLKS-DIRTY-QTIME
disk process writes the dirty cache block to disk, the block
is clean.
Accumulating(ZMS Style only) Number of times a required block is in
cache for a write operation, which saves a found clean
disk read per write.
WRITE-CLEANS
Accumulating(ZMS Style only) Number of times a required block is found
dirty in cache for a write operation.
WRITE-DIRTYS
Accumulating(ZMS Style only) Number of times a required block is not
found in cache for a write operation, which requires a disk
read before the write can be performed.
WRITE-MISSES
In Measure output, each subfield provides eight values, one for each size of DP2 cache block:
Cache block sizeField label
512 bytesC0
1024 bytesC1
2048 bytesC2
4096 bytesC3
8192 bytesC4
16346 bytesC5
32768 bytesC6
65536 bytesC7
DISC 197