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# vVol metrics

Unisphere collects and displays metrics for vVols.

Within the PM metrics section, V4 is used to denote that the metric is supported only by a storage system (array) running PowerMaxOS 10 (6079). V3 is used to denote that the metric is supported only by a storage system (array) running HYPERMAX OS 5977 or PowerMaxOS 5978. Metrics without the denotation are supported by all storage systems (arrays).

The following table lists all metrics that are available for vVols.

Table 1. vVol metrics
Metric | Description
--- | ---
% Hit | The percent of operations that were immediately satisfied by cache
% Miss | The percent of operations that were misses. A miss occurs when the operation cannot be immediately satisfied from cache because the data is not there or the operation has to wait while data is destaged from cache to disks.
% Random IO | The percent of I/O operations that were random
% Random Read Hit | Calculated value: 100 * (random read hits per sec/total I/O operations per second per sec).
% Random Read Miss | Calculated value: 100 * (random read misses per sec/total I/O operations per second per sec).
% Random Reads | The percent of read commands from a host that was not identified as part of a sequential stream.
% Random Write Hit | Calculated value: 100 * (random write hits per sec/total I/O operations per second per sec).
% Random Write Miss | Calculated value: 100 * (random write misses per sec/total I/O operations per second per sec).
% Random Writes | The percent of write commands from a host that was not identified as part of a sequential stream.
% Read Hit | The percentage of read operations, performed by the storage system volume, that were immediately satisfied by cache.
% Read Miss | The percentage of read miss operations performed each second by the storage system volume. A miss occurs when the requested read data is not found in cache or the write operation had to wait while data was destaged from cache to the disks.
% Reads | The percentage of I/O operations that were reads
% Seq Read | Calculated value: 100 * (seq reads per sec/total I/O operations per sec).
% Seq Read Hit | The percent of the sequential read operations that were immediately satisfied from cache.
% Seq Read Miss | The percent of the sequential read operations that were misses.
% Seq Write Hit | The percent of the sequential write operations that were immediately satisfied from cache.
% Seq Write Miss | The percent of the sequential write operations that were misses.
% Seq Writes | Calculated value: 100*(seq writes per sec/total I/O operations per second per sec).
% Sequential IO | Calculated value: 100 * (total seq I/Os per sec/total I/O operations per second per sec)
% Write Hit | The percentage of write operations, performed by the storage system volume, that were immediately satisfied by cache.
% Write Miss | The percent of write miss operations performed each second by the storage system volume. A miss occurs when the write operation had to wait while data was destaged from cache to the disks.
% Writes | The percentage of I/O operations that were writes
Avg IO Size | Calculated value: (HA Kbytes transferred per sec total I/O operations per second per sec)
Avg Read Size | Calculated value: (Kbytes read per sec/total reads per sec)
Avg Write Size | Calculated value: (Kbytes written per sec/total writes per sec)
Avg. Write Paced Delay (ms) | Average write paced delay (V3).
BE Prefetched Throughput | The number of MBs prefetched from disk to cache per second.
BE Prefetched Tracks Used/sec | The number of pre-fetched tracks used each second from the disk directors to the cache
BE Prefetched Tracks/sec | The total pre-fetched tracks each second from the disk directors to the cache.
BE Read Reqs/sec | The number of read requests each second that were performed by the disk directors to the cache.
BE Reqs/sec | The number of read/write requests each second that were performed by the disk directors to the cache.
BE Throughput Read | The number of MBs read by the disk directors from the disk each second
BE Throughput Transferred | The number of MBs read per sec + MBs written per sec.
BE Throughput Written | The number of MBs written to the disk from the disk director each second
BE Write Reqs/sec | The number of write requests each second performed by the disk directors to the cache.
Device Block Size | The block size of the volume
Effective Used Capacity | The effective used capacity
External Read RT | The time it takes to process a read outside of the system (V4)
External Response Time | The time it takes to process an IO request outside of the system (V4)
External Write RT | The time it takes to process a write outside of the system (V4)
Host Hits/sec | The total number of host read I/O and write I/O operations performed each second by the storage system volume that were immediately satisfied by cache.
Host IOs/sec | The total number of host read I/O and write I/O operations performed each second by the volume.
Host Misses/sec | The total number of host read I/O and write I/O operations that were missed each second by the storage system volume.
Host Read Hits/sec | The total number of host read I/O operations that were performed each second by the storage system volume that were immediately satisfied by cache.
Host Read Misses/sec | The total number of host read I/O operations that were missed each second by the storage system volume.
Host Reads/sec | The total number of host read I/O operations that were performed each second by the storage system volume.
Host Throughput | The cumulative number of host MBs read/writes per second
Host Throughput Read | The cumulative number of host MBs read per second
Host Throughput Written | The cumulative number of host MBs written per second
Host Write Hits/sec | The total number of host write I/O operations that were performed each second by the storage system volume that were immediately satisfied by cache.
Host Write Misses/sec | The total number of host write I/O operations that were missed each second by the storage system volume.
Host Writes/sec | The total number of host write I/O operations that were performed each second by the storage system volume.
Internal Read RT | The time it takes to process a read inside of the system (V4)
Internal Response Time | The time it takes to process an IO request inside of the system (V4)
Internal Write RT | The time it takes to process a write inside of the system (V4)
Max WP Capacity Threshold | The capacity of the maximum number of write-pending slots available
Max WP Threshold | The maximum number of write-pending slots available for the storage system volume
Number of RDF Invalid Tracks | Number of SRDF invalid tracks (V3)
Random Hits/sec | The total number of hits per second that were not sequential.
Random IOs/sec | The number of I/O operations per second from a host that were not identified as part of a sequential stream.
Random Read Hits/sec | The number of random read I/Os that were satisfied from the cache.
Random Read Misses/sec | The number of random read I/Os that were misses.
Random Reads/sec | The number of read I/O commands from a host that is not identified as part of a sequential stream.
Random Write Hits/sec | The number of random write I/O operations per second that were immediately placed in cache because space was available.
Random Write Misses/sec | The number of random write I/O operations per second that were misses.
Random Writes/sec | The number of write I/O commands from a host that was not identified as part of a sequential stream.
RDF MBs Read/sec | SRDF MBs read per second (V3)
RDF MBs Written/sec | SRDF MBs written per seconds (V3)
RDF Reads/sec | SRDF reads per second (V3).
RDF Response Time (ms) | The SRDF round- trip time - the metric is calculated as follows : SRDF Accumulated Service Time/(SRDF Reads/sec + SRDF Writes/sec) rolled up from the SRDF devices in the group (V3)
RDF Rewrites/sec | SRDF rewrites per second (V3).
RDF Writes/sec | SRDF writes per second (V3).
RDF/S Write RT (ms) | The average time that it took the volume to serve one write I/O (V3).
Read Miss RT | The average time a read miss operation was performed by the volume. A miss occurs when the requested data is not found in cache.
Read RT | The average time a read operation was performed by the volume.
Seq IOs/sec | The number of I/O operations performed each second that were sequential.
Seq Read Hits/sec | The number of sequential read operations performed each second by the storage system volume that were immediately satisfied from cache.
Seq Read Miss/sec | The number of sequential read operations performed each second by the storage system volume that were misses.
Seq Reads/sec | The number of read I/O operations performed each second that were sequential.
Seq Write Hits/sec | The number of sequential write operations performed each second by the storage system volume that were immediately satisfied from cache.
Seq Write Misses/sec | The number of sequential write operations performed each second by the storage system volume that were misses.
Seq Writes/sec | The number of write I/O operations performed each second that were sequential.
Total Capacity | The total capacity of the volume
WP Count | The number of tracks in write pending mode for the volume.
WP Used Capacity | The write pending used capacity
Write Miss RT | The average time a write miss operation was performed by the volume. A miss occurs when the write operation has to wait while data is destaged from cache to disks.
Write Paced Delay (ms) | Write paced delay (V3).
Write RT | The average time that it took the system to serve one write I/O for this volume.