Host IOs/sec

Number of host IO operations performed each second   by all Symmetrix devices, including writes and random and sequential reads.

Host Reads/sec

Number of host read operations performed each second   by all Symmetrix devices.

Host Writes/sec

Number of host write operations performed each second   by all Symmetrix devices.

% Reads

Percent of total read IO operations performed each   second by all of the Symmetrix devices.

% Writes

Percent of total write IO operations performed by   all of the Symmetrix devices.

% Hit

Percent of IO operations performed by all of the   Symmetrix devices, for which the read data was in cache and the write   operation could be sent directly to cache without having to wait for data   to be destaged from cache to the disks.

Host MBs/sec

The number of host MBs written and read by all of   the Symmetrix devices each second.

Host MBs Read/sec

The number of host MBs read by all of the Symmetrix   devices each second.

Host MBs Written/sec

The number of host MBs written by all of the Symmetrix   devices each second.

FE Reqs/sec

Data transfer between the director and the cache.   An IO may require multiple requests depending on IO size, alignment, or   both. The requests rate should be either equal to or greater than the   IO rate.

FE Read Reqs/sec

A read data transfer between the director and the   cache. An IO may require multiple requests depending on IO size, alignment,   or both. The requests rate should be either equal to or greater than the   IO rate.

FE Write Reqs/sec

A write data transfer between the director and the   cache. An IO may require multiple requests depending on IO size, alignment,   or both. The requests rate should be either equal to or greater than the   IO rate.

BE IOs/sec

Total IO from all BE directors to the disks per second.

BE Reqs/sec

A data transfer of a read or write between the cache   and the director.

BE Read Reqs/sec

A data transfer of a read between the cache and the   director.

BE Write Reqs/sec

A data transfer of a write between the cache and   the director.

System WP Events/sec

Number of times each second that write activity was   heavy enough to use up the system limit set for write tracks occupying   cache. When the limit is reached, writes are deferred until data in cache   is written to disk.

Device WP Events/sec

Number of times each second that the write-pending   limit for a specific Symmetrix device was reached.

WP Count

Number of system cache slots that are write pending.

System Max WP limit

The percent of the target % at which writes are delayed.   The range is from 40% to 80%.

% Cache WP

Percent of system cache that is write pending.

Avg Fall Thru Time

Average time it takes a cache slot in LRU0 to be   freed up. It is the average time from the first use of the contents to   its reuse by another address.

FE Hit Req/sec

Total requests from all FE directors per second that   were satisfied from cache.

FE Read Hit Reqs/sec

Total read requests from all FE directors per second   that were satisfied from cache.

FE Write Hit Reqs/sec

Total write requests from all FE directors per second   that were satisfied from cache.

Prefetched Tracks/sec

Tracks per second pre-fetched from disk to cache   upon detection of a sequential read stream.

Destaged Tracks/sec

Tracks per second saved into disks.

FE Read Miss Reqs/sec

Total read requests from all FE directors per second   that were misses. A miss occurs when the requested read data is not found   in cache.

FE Write Miss Reqs/sec

Total write requests from all FE directors per second   that were misses.  A miss occurs when the write   operation had to wait while data was destaged from cache to the disks.