FE Director metrics

Unisphere collects and displays metrics for FE directors.

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 FE directors.

Table 1. FE director metrics
Metric Description
% Busy The percent of time the director is busy (numerator_delta/denominator_delta) * 100 (V4)
% Hit Reqs The percentage of requests that are served from cache
% Read Req Hit The percentage of read requests that are served from cache
% Read Reqs The percentage of read requests out of host commands for data transfer
% Write Req Hit The percentage of write requests that were satisfied from cache
% Write Reqs The percentage of write requests out of host commands for data transfer.
Avg Optimized Read Miss Size Average optimized read miss size
Avg Queue Depth Range 0 The average queue depth that is seen for all I/O requests entering the FE director, for each bucket/range for each collection/timestamp
Avg Queue Depth Range 1 The average queue depth that is seen for all I/O requests entering the FE director, for each bucket/range for each collection/timestamp
Avg Queue Depth Range 2 The average queue depth that is seen for all I/O requests entering the FE director, for each bucket/range for each collection/timestamp
Avg Queue Depth Range 3 The average queue depth that is seen for all I/O requests entering the FE director, for each bucket/range for each collection/timestamp
Avg Queue Depth Range 4 The average queue depth that is seen for all I/O requests entering the FE director, for each bucket/range for each collection/timestamp
Avg Queue Depth Range 5 The average queue depth that is seen for all I/O requests entering the FE director, for each bucket/range for each collection/timestamp
Avg Queue Depth Range 6 The average queue depth that is seen for all I/O requests entering the FE director, for each bucket/range for each collection/timestamp
Avg Queue Depth Range 7 The average queue depth that is seen for all I/O requests entering the FE director, for each bucket/range for each collection/timestamp
Avg Queue Depth Range 8 The average queue depth that is seen for all I/O requests entering the FE director, for each bucket/range for each collection/timestamp
Avg Queue Depth Range 9 The average queue depth that is seen for all I/O requests entering the FE director, for each bucket/range for each collection/timestam
Avg RDF Write Time SRDF write time per second/SRDF write waits per second
Avg Read Miss Time Read miss time per second/read miss waits per second
Avg Time per Syscall The average time that it took to serve one system call
Avg WP Disconnect Time Write Pending disconnect time per second/ WP disconnects per second
Avg Write RT 16 to 32 Average write response time 16–32
CCWS Per IO CCWS per I/O
Device WP Events/sec A write miss due to the volume write pending limit having been reached
Hits Reqs/sec A request that is immediately serviced from the cache (instead of having to wait for the data to arrive, or destage from the disk)
Host IO Limit IOs/sec The number of I/Os the FE director is processing 
Host IO Limit Throughput The number of MBs the FE port is processing
Host IOs/sec A host command for data transfer
Host Throughput The size of the data transfer from the host in MBs per second
Miss Reqs/sec A request that is a miss
Optimized Read Misses/sec Number of read requests each second performed directly from disks bypassing the cache
Optimized Throughput Read Miss Number of host MBs read each second directly from disks bypassing the cache
ORS ASync IOs/sec ORS ASync I/Os per second
ORS ASync Throughput ORS Async throughput
ORS Sync IOs/sec ORS Sync I/Os per second (V4)
ORS Sync Throughput ORS Sync throughput (V4)
Queue Depth Count Range 0-9 As an I/O enters the queue, it first checks how deep the queue is. After incrementing the queue depth bucket, it increments the associated count bucket by 1. This metric represents the number of I/Os that encountered queues of certain depth during the past time interval. The intent of these buckets is to identify I/Os bursts which in turn generate large queues and long response times.
Queue Depth Count Range 0 This metric provides an average representation of the burstiness of the I/Os that may be causing FE director queuing
Queue Depth Count Range 1 This metric provides an average representation of the burstiness of the I/Os that may be causing FE director queuing
Queue Depth Count Range 2 This metric provides an average representation of the burstiness of the I/Os that may be causing FE director queuing
Queue Depth Count Range 3 This metric provides an average representation of the burstiness of the I/Os that may be causing FE director queuing
Queue Depth Count Range 4 This metric provides an average representation of the burstiness of the I/Os that may be causing FE director queuing
Queue Depth Count Range 5 This metric provides an average representation of the burstiness of the I/Os that may be causing FE director queuing
Queue Depth Count Range 6 This metric provides an average representation of the burstiness of the I/Os that may be causing FE director queuing
Queue Depth Count Range 7 This metric provides an average representation of the burstiness of the I/Os that may be causing FE director queuing
Queue Depth Count Range 8 This metric provides an average representation of the burstiness of the I/Os that may be causing FE director queuing
Queue Depth Count Range 9 This metric provides an average representation of the burstiness of the I/Os that may be causing FE director queuing
Queue Depth Utilization A weighted sum of the utilizations according to the number of I/Os in each bucket - Queue depth range metrics are used in the calculation. Calculation: Sx=1..9 [(Avg Queue Depth Range X - 1) / Avg Queue Depth Range X] * (Queue Depth Count Range X/Queue Depth Count Total) * 100 
Random Write Throughput to non WP Slots Random MBs throughput to non-WP slots
Random Write Thoughput to WP Slots Random MBs throughput to WP slots
Random Writes to non WP Slots/sec Random writes to non-WP slots per second
Random Writes to WP Slots/sec Random writes to WP slots per second
Read Hit Reqs/sec A read request that is immediately serviced from the cache (instead of having to wait for the data to arrive from the disk)
Read Miss Reqs/sec A read request that cannot be satisfied immediately from the cache and must wait for the data to arrive from the disk
Read Reqs/sec A read data transfer that occurs between the director and the cache. An I/O may require multiple requests depending on I/O size, alignment or both. The requests rate should be either equal to or greater than the I/O rate
Read RT The calculated average response time for reads
Read RT 0 to 1 These buckets show the distribution of the number of reads to the FE directors over the specified time range.
Read RT 1 to 2 These buckets show the distribution of the number of reads to the FE directors over the specified time range.
Read RT 16 to 32 These buckets show the distribution of the number of reads to the FE directors over the specified time range.
Read RT 2 to 4 These buckets show the distribution of the number of reads to the FE directors over the specified time range.
Read RT 32 to 64 These buckets show the distribution of the number of reads to the FE directors over the specified time range.
Read RT 4 to 8 These buckets show the distribution of the number of reads to the FE directors over the specified time range.
Read RT 8 to 16 These buckets show the distribution of the number of reads to the FE directors over the specified time range.
Read RT Count Range 0 to 1 These buckets show the distribution of the number of reads to the FE directors over the specified time range.
Read RT Count Range 1 to 2 These buckets show the distribution of the number of reads to the FE directors over the specified time range.
Read RT Count Range 16 to 32 These buckets show the distribution of the number of reads to the FE directors over the specified time range.
Read RT Count Range 2 to 4 These buckets show the distribution of the number of reads to the FE directors over the specified time range.
Read RT Count Range 32 to 64 These buckets show the distribution of the number of reads to the FE directors over the specified time range.
Read RT Count Range 4 to 8 These buckets show the distribution of the number of reads to the FE directors over the specified time range.
Read RT Count Range 8 to 16 These buckets show the distribution of the number of reads to the FE directors over the specified time range.
Read RT Count Range Over 64 These buckets show the distribution of the number of reads to the FE directors over the specified time range.
Read RT Over 64 These buckets show the distribution of the number of reads to the FE directors over the specified time range.
Reqs/sec Data transfer that occurs between the director and the cache. An I/O may require multiple requests depending on I/O size, alignment or both. The requests rate should be either equal to or greater than the I/O rate.
Slot Collisions/sec The number of write misses due to the desired cache slot being locked by another request
Syscall Count/sec The total number of calls seen by this director
Syscall RDF Dir Count/sec The number of calls per second sent using SRDF to a remote system
Syscall Remote Dir Count/sec The number of calls per second sent from the local director to another director in the same system
Syscall Time/sec Total time that is spent processing all system calls
System WP Events/sec A write miss due to the system write pending limit having been reached
Total Read Count/sec The total number of reads to the FE directors per second
Total Write Count/sec The total number of writes to the FE directors per second
Write Hit Reqs/sec A write request that is immediately serviced from the cache (instead of having to wait for the data to be destaged to the disk.)
Write Miss Reqs/sec A write request that cannot be satisfied immediately from the cache and must wait for the data to be destaged to the disk.
Write Reqs/sec A write data transfer that occurs between the director and the cache. An I/O may require multiple requests depending on I/O size, alignment or both. The requests rate should be either equal to or greater than the I/O rate.
Write RT The calculated average response time for writes
Write RT 0 to 1 These buckets show the distribution of the number of writes to the FE directors over the specified time range.
Write RT 1 to 2 These buckets show the distribution of the number of writes to the FE directors over the specified time range.
Write RT 2 to 4 These buckets show the distribution of the number of writes to the FE directors over the specified time range.
Write RT 32 to 64 These buckets show the distribution of the number of writes to the FE directors over the specified time range.
Write RT 4 to 8 These buckets show the distribution of the number of writes to the FE directors over the specified time range.
Write RT 8 to 16 These buckets show the distribution of the number of writes to the FE directors over the specified time range.
Write RT Count Range 0 to 1 These buckets show the distribution of the number of writes to the FE directors over the specified time range.
Write RT Count Range 1 to 2 These buckets show the distribution of the number of writes to the FE directors over the specified time range.
Write RT Count Range 16 to 32 These buckets show the distribution of the number of writes to the FE directors over the specified time range.
Write RT Count Range 2 to 4 These buckets show the distribution of the number of writes to the FE directors over the specified time range.
Write RT Count Range 32 to 64 These buckets show the distribution of the number of writes to the FE directors over the specified time range.
Write RT Count Range 4 to 8 These buckets show the distribution of the number of writes to the FE directors over the specified time range.
Write RT Count Range 8 to 16 These buckets show the distribution of the number of writes to the FE directors over the specified time range.
Write RT Count Range Over 64 These buckets show the distribution of the number of writes to the FE directors over the specified time range.
Write RT Over 64 These buckets show the distribution of the number of writes to the FE directors over the specified time range.
ZHPF Read Throughput High Performance FICON Read Throughput/sec
ZHPF Reads High Performance FICON Reads
ZHPF Write Throughput High Performance FICON Write Throughput/sec
ZHPF Writes High Performance FICON Writes