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# Storage Resource metrics

Unisphere collects and displays metrics for storage resources.

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 storage resources.

Table 1. Storage resources metrics
Metric | Description
--- | ---
% Hit | The percent of I/O operations that were immediately satisfied from cache
% Miss | The percent of I/O operations that were misses
% 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 sec).
% Random Read Miss | Calculated value: 100 * (random read misses per sec/total I/O operations per sec).
% Random Reads | The percent of all read I/Os that were random.
% Random Write Hit | Calculated value: 100 * (random write hits per sec/total I/O operations per sec).
% Random Write Miss | Calculated value: 100 * (random write misses per sec/total I/O operations per sec).
% Random Writes | The percent of all write I/O operations per second that were random.
% Read Hit | The percent of read operations, performed by the group, that were immediately satisfied by cache
% Read Miss | The percent of read miss operations performed each second by the group. A miss occurs when the requested read data is not found in cache.
% Reads | The percent of I/O operations that were reads
% Seq Read | Calculated value: 100 * (seq reads per sec/total I/Os 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/Os per sec).
% Sequential IO | The percent of I/O operations that were sequential
% Virtual Provisioning Space Saved | Percentage virtual provisioning space saved
% Write Hit | The percent of write operations, performed by the group, that were immediately satisfied by cache.
% Write Miss | The percent of write miss operations performed each second by the group. A miss occurs when the write operation had to wait while data was destaged from cache to the disks.
% Writes | The percent of I/O operations that were writes
Allocated Capacity | The total allocated storage group capacity
Async MBs Sent/sec | The number of async MBs sent per second using this storage group (V3)
Async Write Reqs/sec | The number of async write requests managed by this storage group per second (V3).
Avg IO Size | Calculated value: (HA Kbytes transferred per sec /total I/Os 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 % Reads | The percent of the back-end I/O that were read requests
BE % Writes | The percent of the back-end I/O that were write requests
BE Optimize Write Throughput | Internal metric
BE Partial Sector Writes (KB) | The KBs of back-end I/O that were partial sector writes (V3)
BE Prefetched Throughput | The number of tracks per second prefetched from disk to cache upon detection of a sequential read stream
BE Prefetched Tracks Used/sec | The number of prefetched tracks used each second from the disk directors to the cache
BE Prefetched Tracks/sec | Total prefetched tracks each second from the disk directors to the cache.
BE RDF Copy | Internal metric (V3)
BE RDF Copy (MB) | Internal metric (V3)
BE Read Reqs/sec | The number of read requests each second performed by the disk directors to cache.
BE Read Throughput | BE Read Throughput
BE Reads For Copy/sec | BE Reads For Copy/sec
BE Reqs/sec | The number of read/write requests each second performed by the disk directors to cache.
BE Throughput Read For Copy | BE Throughput Read For Copy
BE Throughput Transferred | BE Throughput Transferred
BE Throughput Written | BE Throughput Written
BE Throughput Written For Copy | BE Throughput Written For Copy
BE Write Reqs/sec | The number of write requests each second performed by the disk directors to cache.
BE Writes Throughput For Rebuild | BE Writes Throughput For Rebuild
BE Writes For Copy/sec | Internal metric
BE Writes For Rebuild/sec | Internal metric
Compression Ratio |
| NOTE: Compression ratio metrics are supported only on systems capable of compression. Any value reported on a system that is not capable of compression should be disregarded.
Critical Alert Count | Number of critical alerts
Device Block Size | The block size of the volume
External Read RT | The time that it takes to process a read outside of the system (V4)
External Response Time | The time that it takes to process an IO request outside of the system (V4)
External Write RT | The time that it takes to process a write outside of the system (V4)
Host Hits/sec | The number of host read/write operations performed each second by the group that were immediately satisfied from cache.
Host IO Limit % Time Exceeded | Host I/O Limit percentage time exceeded
Host IO Limit IOs/sec | The number of I/O operations per second the FE port is processing on behalf of the specific storage group.
Host IO Limit Throughput | Host I/O Limit Throughput
Host IO Limit Time Exceeded | The number of I/O operations per second the FE port is performing on behalf of the specific storage group.
Host IOs/sec | The number of host operations performed each second by the group
Host Misses/sec | The number of host read/write operations performed each second by the group that could not be satisfied from cache
Host Read Hits/sec | The number of host read operations performed each second by the group that were immediately satisfied from cache.
Host Read Misses/sec | The number of host read operations performed each second by the group that were not satisfied from cache.
Host Reads/sec | The number of host read operations performed each second by the group.
Host Throughput | Host throughput
Host Throughput Read/sec | Host Throughput Read/sec
Host Throughput Written | Host Throughput Written
Host Write Hits/sec | The number of host write operations performed each second by the group that were immediately satisfied from cache.
Host Write Misses/sec | The number of host write operations performed each second by the group that were not satisfied from cache.
Host Writes/sec | The number of host write operations performed each second by the group.
Information Alert Count | Number of information alerts
Internal Read RT | The time that it takes to process a read inside of the system (V4)
Internal Response Time | The time that it takes to process an IO request inside of the system (V4)
Internal Write RT | The time that it takes to process a write inside of the system (V4)
IO Density | The number of BE requests per GB of disk
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 group
Random IOs/sec | I/O operations per second from a host that is not identified as part of a sequential stream
Random Read Hits/sec | Random read I/O operations per second that were satisfied from the cache
Random Read Misses/sec | Random read I/O operations per second that were misses
Random Reads/sec | Read I/O commands from a host that is not identified as part of a sequential stream.
Random Write Hits/sec | Random write I/O operations per second that were immediately placed in cache because space was available.
Random Write Misses/sec | Random write I/O operations per second that were misses.
Random Writes/sec | Write I/O commands from a host that is 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 second (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) | A summary of the read, write, and average response times for the selected SRDF/S group (V3).
Read Miss RT | The average time that it took the storage to serve one read miss I/O for this group.
Read RT | The calculated average read response time
Read RT 14 to 32 | Read RT 14—32
Read RT Count 0 to 1 | Read RT Count 0—1
Read RT Count 1 to 3 | Read RT Count 1—3
Read RT Count 14 to 32 | Read RT Count 14—32
Read RT Count 3 to 5 | Read RT Count 3—5
Read RT Count 5 to 8 | Read RT Count 5—8
Read RT Count 8 to 14 | Read RT Count 8—14
Read RT Count Over 32 | Read RT Count Over 32
Read RT Over 32 | Read RT Over 32
Response Time | The calculated average response time
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 group that were immediately satisfied from cache
Seq Read Miss/sec | The number of sequential read operations performed each second by the group 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 group that were immediately satisfied from cache
Seq Write Misses/sec | The number of sequential write operations performed each second by the group that were misses
Seq Writes/sec | The number of write I/O operations performed each second that were sequential.
Skew | Skew (V3)
Sync MBs Sent/sec | The number of sync MBs sent per second using this storage group (V3)
Sync Write Reqs/sec | The number of sync write requests per second (V3).
Total Capacity | The total capacity of the storage group
Total Tracks | The total number of tracks for the storage group
Warning Alert Count | Number of warning alerts
WP Count | The number of tracks in write pending mode for the group.
WP Used Capacity | WP used capacity
Write Miss RT | The average time that it took the storage to serve one write miss I/O for this group.
Write paced delay | Write paced delay (V3).
Write RT | The calculated average write response time
Write RT 14 to 32 | Write RT 14—32
Write RT Count 0 to 1 | Write RT Count 0—1
Write RT Count 1 to 3 | Write RT Count 1—3
Write RT Count 14 to 32 | Write RT Count 14—32
Write RT Count 3 to 5 | Write RT Count 14—32
Write RT Count 5 to 8 | Write RT Count 5—8
Write RT Count 8 to 14 | Write RT Count 8—14.
Write RT Count Over 32 | Write RT Count Over 32
Write RT Over 32 | Write RT Over 32

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