Performance metrics

Metrics data available in the Performance dashboard provides health and performance information for the IBM® storage objects.

Different metric types are available for different storage elements, as detailed in tables below.

Table 1. Capacity metrics
Metrics Description Relevant storage object
Hard (GB) Hard size (actual physical capacity) of the storage object Volume, Pool, Array
Soft (GB) Soft size (maximum capacity) of the storage object, as seen by the hosts
Utilization Hard (%) Utilization ratio of the hard capacity
Utilization Soft (%) Utilization ratio of the soft capacity
Free Hard (GB) Free hard size of the storage system (array) Array
Free Soft (GB) Free soft size of the storage system
Over Provisioning Ratio (%) The ratio between virtual capacity and real capacity of the pool Pool
Compression Ratio (%) Volume compression ratio, calculated as 1–(compressed volume size/uncompressed volume size) Volume
Compression Saving (GB) Volume compression savings, calculated as (number of 17GB uncompressed partitions in use – number of 17GB partitions in use)/1000
Effective (GB) Potential capacity of the storage object IBM FlashSystem A9000/A9000R Array or Volume
Physical (GB) Actual physical capacity of the storage object
Utilization Effective (%) Utilization ratio of the effective capacity
Utilization Physical (%) Utilization ratio of the physical capacity
Thin Provisioning Savings (%) Total savings achieved due to thin provisioning
Free Effective (GB) Free effective size of the storage system IBM FlashSystem A9000/A9000R Array
Free Physical (GB) Free physical size of the storage system
Compression Factor Ratio between unique data (after deduplication) and actual stored data
Data Reduction Savings (%) Total savings achieved due to data reduction
Total Stored (GB) Actual size of data currently stored on the system
Total Written (GB) Total amount of data written by hosts before compression or deduplication
Estimated Compression Factor Ratio between unique data and physical data IBM FlashSystem A9000/A9000R Volume
Estimated Deduplication Factor Ratio between written and unique data
Estimated Minimum Delete Size (GB) Amount of unique written data divided by estimated compression factor
Estimated Data Reduction Savings (%) Estimated savings due to data reduction
Table 2. Health metrics
Metrics Description Relevant storage object
Connected Connection status of the object Host, Host FC Initiator, Host iSCSI Initiator
Status Health status of the module Module, IBM Spectrum Virtualize MDisk
Requires Service Heath status of the disk. The REPLACE value indicates disk failure. Disk
Online Connection status of the object. For IBM Spectrum Virtualize Host, the status can be as follows:
  • 0 – Offline
  • 5 – Excluded
  • 10 – Degraded
  • 20 – Is Online
 Module FC Port, Module iSCSI Port, IBM Spectrum Virtualize Node FC Port, IBM Spectrum Virtualize Node iSCSI Port, IBM Spectrum Virtualize Host
Table 3. Counter metrics
Metrics Description Relevant storage object
Hosts Count Total number of hosts connected to the storage system Array, IBM Spectrum Virtualize I/O Group
Volumes Count Total number of volumes existing in the storage system
Mirror Relations Count Total number of mirror relations (master or slave) existing in the storage system Array
Pools Count Total number of pools existing in the storage system
Snapshots Count Total number of snapshots existing in the storage system
Volumes and Snapshots Count Total number of volumes and snapshots existing in the storage system
Nodes Count Total number of nodes in the I/O group IBM Spectrum Virtualize I/O Group
Table 4. Performance metrics
Metrics Description Relevant storage object
Total IOPS Total number of IOPS performed by the object Array, Host FC Initiator, Host iSCSI Initiator, Module FC Port, Module iSCSI Port
Total Read IOPS Total number of read IOPS performed by the object
Total Write IOPS Total number of write IOPS performed by the object
Read Hit Large IOPS Number of IOPS for 64–512 KB packets read from cache
Read Hit Medium IOPS Number of IOPS for 8–64 KB packets read from cache
Read Hit Small IOPS Number of IOPS for 0–8 KB packets read from cache
Read Hit Very Large IOPS Number of IOPS for over 512 KB packets read from cache
Read Miss Large IOPS Number of IOPS for 64–512 KB packets read from disk
Read Miss Medium IOPS Number of IOPS for 8–64 KB packets read from disk
Read Miss Small IOPS Number of IOPS for 0–8 KB packets read from disk
Read Miss Very Large IOPS Number of IOPS for over 512 KB packets read from disk
Write Hit Large IOPS Number of IOPS for 64–512 KB packets written to cache
Write Hit Medium IOPS Number of IOPS for 8–64 KB packets written to cache
Write Hit Small IOPS Number of IOPS for 0–8 KB packets written to cache
Write Hit Very Large IOPS Number of IOPS for over 512 KB packets written to cache
Write Miss Large IOPS Number of IOPS for 64–512 KB packets written to disk
Write Miss Medium IOPS Number of IOPS for 8–64 KB packets written to disk
Write Miss Small IOPS Number of IOPS for 0–8 KB packets written to disk
Write Miss Very Large IOPS Number of IOPS for over 512 KB packets written to disk
Average Latency Average response time
Average Write Latency Average response time of a write operation
Average Read Latency Average response time of a read operation
Read Hit Large Latency Response time of cache read operations for 64–512 KB packets
Read Hit Medium Latency Response time of cache read operations for 8–64 KB packets
Read Hit Small Latency Response time of cache read operations for 0–8 KB packets
Read Hit Very Large Latency Response time of cache read operations for over 512 KB packets
Read Memory Hit Large Latency Response time of DRAM cache read operations for 64–512 KB packets Array
Read Memory Hit Medium Latency Response time of DRAM cache read operations for 8–64 KB packets
Read Memory Hit Small Latency Response time of DRAM cache read operations for 0–8 KB packets
Read Memory Hit Very Large Latency Response time of DRAM cache read operations for over 512 KB packets
Read Miss Large Latency Response time of disk read operations for 64–512 KB packets Array, Host FC Initiator, Host iSCSI Initiator, Module FC Port, Module iSCSI Port
Read Miss Medium Latency Response time of disk read operations for 8–64 KB packets
Read Miss Small Latency Response time of disk read operations for 0–8 KB packets
Read Miss Very Large Latency Response time of disk read operations for over 512 KB packets
Write Hit Large Latency Response time of cache write operations for 64–512 KB packets
Write Hit Medium Latency Response time of cache write operations for 8–64 KB packets
Write Hit Small Latency Response time of cache write operations for 0–8 KB packets
Write Hit Very Large Latency Response time of cache write operations for over 512 KB packets
Write Miss Large Latency Response time of disk write operations for 64–512 KB packets
Write Miss Medium Latency Response time of disk write operations for 8–64 KB packets
Write Miss Small Latency Response time of disk write operations for 0–8 KB packets
Write Miss Very Large Latency Response time of disk write operations for over 512 KB packets
Total Throughput Total bandwidth
Total Read Throughput Total bandwidth used by read operations
Total Write Throughput Total bandwidth used by write operations
Read Hit Large Throughput Bandwidth used by cache read operations for 64–512 KB packets
Read Hit Medium Throughput Bandwidth used by cache read operations for 8–64 KB packets
Read Hit Small Throughput Bandwidth used by cache read operations for 0–8 KB packets
Read Hit Very Large Throughput Bandwidth used by cache read operations for over 512 KB packets
Read Memory Hit Large Throughput Bandwidth used by DRAM cache read operations for 64–512 KB packets Array
Read Memory Hit Medium Throughput Bandwidth used by DRAM cache read operations for 8–64 KB packets
Read Memory Hit Small Throughput Bandwidth used by DRAM cache read operations for 0–8 KB packets
Read Memory Hit Very Large Throughput Bandwidth used by DRAM cache read operations for over 512 KB packets
Read Miss Large Throughput Bandwidth used by disk read operations for 64–512 KB packets Array, Host FC Initiator, Host iSCSI Initiator, Module FC Port, Module iSCSI Port
Read Miss Medium Throughput Bandwidth used by disk read operations for 8–64 KB packets
Read Miss Small Throughput Bandwidth used by disk read operations for 0–8 KB packets
Read Miss Very Large Throughput Bandwidth used by disk read operations for over 512 KB packets
Write Hit Large Throughput Bandwidth used by cache write operations for 64–512 KB packets
Write Hit Medium Throughput Bandwidth used by cache write operations for 8–64 KB packets
Write Hit Small Throughput Bandwidth used by cache write operations for 0–8 KB packets
Write Hit Very Large Throughput Bandwidth used by cache write operations for over 512 KB packets
Write Miss Large Throughput Bandwidth used by disk write operations for 64–512 KB packets
Write Miss Medium Throughput Bandwidth used by disk write operations for 8–64 KB packets
Write Miss Small Throughput Bandwidth used by disk write operations for 0–8 KB packets
Write Miss Very Large Throughput Bandwidth used by disk write operations for over 512 KB packets
Aborts Total number of I/Os aborted during the current mirroring operation
Failures Total number of I/Os failed during the current mirroring operation
Read Operations Number of read operations per second IBM Spectrum Virtualize Vdisk
Write Operations Number of write operations per second
Read Blocks Number of blocks read per second (in MB)
Write Blocks Number of blocks written per second (in MB)
Average Read Response Time Average response time for disk reads per read operation
Average Write Response Time Average response time for disk writes per write operation
Worst Read Response Time Since Last Statistics Collection Worst response time for disk reads within the last statistics collection sample period
Worst Write Response Time Since Last Statistics Collection Worst response time for disk writes within the last statistics collection sample period
Average Transfer Response Time Average transfer latency for both read and write operations
System CPU Utilization CPU busy percentage for I/O process cores IBM Spectrum Virtualize Node
Compression CPU Utilization CPU busy percentage for compression process cores