Performance metrics for SAN Volume Controller and Storwize systems

A storage environment can include SAN Volume Controller systems, Storwize V7000 systems, and a Storwize V7000 Unified systems. You can include performance metrics for ports, port errors, volumes, caches, back-end arrays, and other data for these systems in performance reports.

Port data

You can create performance reports that include the following information:

Port Send I/O Rate (ops/s): The average number of I/O operations per second for operations in which data is sent from a port.A send operation is a read operation that is processed, or a write operation that is initiated by the port.
Port Receive I/O Rate (ops/s): The average number of I/O operations per second for operations in which the port receives data.A receive operation is a write operation that is processed, or a read operation that is initiated by the port.
Total Port I/O Rate (ops/s): The average number of send operations and receive operations per second.
Port to Host Send I/O Rate (ops/s): The average number of IOs per second that are sent by the storage system to the hosts that are accessing its storage. Use this metric to help measure host workload against the storage system.
Port to Host Receive I/O Rate (ops/s): The average number of IOs per second that are received by the storage system from the hosts that are accessing its storage. Use this metric to help measure host workload against the storage system.
Total Port to Host I/O Rate (ops/s): The average number of IOs per second that are transmitted between the storage system and the hosts that are accessing its storage. Use this metric to help measure host workload against the storage system.
Port to Disk Send I/O Rate (ops/s): The average number of IOs per second that are sent from the storage system to the back-end storage it is virtualizing. Use this metric to help measure the rate of data that is sent to back-end storage.
Port to Disk Receive I/O Rate (ops/s): The average number of exchanges per second that are received from back-end storage resources.
Total Port to Disk I/O Rate (ops/s): The average number of IOs per second that are transmitted between the storage system and the back-end storage it is virtualizing. Use this metric to help measure the rate of data that is sent to back-end storage.
Port to Local Node Send I/O Rate (ops/s): The average number of IOs per second that are sent to other nodes within the local cluster. Use this metric to understand the rate of inter-cluster communication.
Port to Local Node Receive I/O Rate (ops/s): The average number of IOs per second that are received from other nodes within the local cluster. Use this metric to understand the rate of inter-cluster communication.
Total Port to Local Node I/O Rate (ops/s): The average number of IOs per second that are transmitted between the resource and other nodes within the local cluster. Use this metric to understand the rate of inter-cluster communication.
Port to Remote Node Send I/O Rate (ops/s): The average number of IOs per second that are sent to nodes that are in a remote cluster. Use this metric to understand the amount of remote replication workload.
Port to Remote Node Receive I/O Rate (ops/s): The average number of IOs per second that are received from nodes that are in a remote cluster. Use this metric to understand the amount of remote replication workload.
Total Port to Remote Node I/O Rate (ops/s): The average number of IOs per second that are transmitted between the resource and nodes that are in a remote cluster. Use this metric to understand the amount of remote replication workload.
Port Send Data Rate (MiB/s): The average rate at which data is sent from the port. The rate is measured in MiB per second. A send operation is a read operation that is processed, or a write operation that is initiated by the port.
Port Receive Data Rate (MiB/s): The average rate at which data is received by the port. The rate is measured in MiB per second. A receive operation is a write operation that is processed, or a read operation that is initiated by the port.
Total Port Data Rate (MiB/s): The average rate at which data is transferred through the port. The rate is measured in MiB per second and includes both send and receive operations.
Port to Host Send Data Rate (MiB/s): The average rate at which data is sent to host computers. The rate is measured in MiB per second.
Port to Host Receive Data Rate (MiB/s): The average rate at which data is received from host computers. The rate is measured in MiB per second.
Total Port to Host Data Rate (MiB/s): The average rate at which data is transmitted between host computers and the component. The rate is measured in MiB per second and includes both send and receive operations.
Port to Disk Sph_port_send_bandwidth_percentageend Data Rate (MiB/s): The average rate at which data is sent to back-end storage resources. The rate is measured in MiB per second.
Port to Disk Receive Data Rate (MiB/s): The average rate at which data is received from back-end storage resources. The rate is measured in MiB per second.
Total Port to Disk Data Rate (MiB/s): The average rate at which data is transmitted between back-end storage resources and the component. The rate is measured in MiB per second and includes both send and receive operations.
Port to Local Node Send Data Rate (MiB/s): The average rate at which data is sent to other nodes that are in the local cluster. The rate is measured in MiB per second.
Port to Local Node Receive Data Rate (MiB/s): The average rate at which data is received from other nodes that are in the local cluster. The rate is measured in MiB per second.
Total Port to Local Node Data Rate (MiB/s): The average rate at which data is transmitted between the component and other nodes that are in the local cluster. The rate is measured in MiB per second.
Port to Remote Node Send Data Rate (MiB/s): The average rate at which data is sent to nodes that are in the remote cluster. The rate is measured in MiB per second.
Port to Remote Node Receive Data Rate (MiB/s): The average rate at which data is received from nodes that are in the remote cluster. The rate is measured in MiB per second.
Total Port to Remote Node Data Rate (MiB/s): The average rate at which data is transmitted between the component and nodes that are in the remote cluster. The rate is measured in MiB per second.
Port to Local Node Send Response Time (ms/op): The average number of milliseconds to complete a send operation to another node that is in the local cluster. This value represents the external response time of the transfers.
Port to Local Node Receive Response Time (ms/op): The average number of milliseconds to complete a receive operation from another node that is in the local cluster. This value represents the external response time of the transfers.
Overall Port to Local Node Response Time (ms/op): The average number of milliseconds to complete a send or receive operation with another node that is in the local cluster. This value represents the external response time of the transfers.
Port to Local Node Send Queue Time (ms/op): The average time in milliseconds that a send operation spends in the queue before the operation is processed. This value represents the queue time for send operations that are issued to other nodes that are in the local cluster.
Port to Local Node Receive Queue Time (ms/op): The average time in milliseconds that a receive operation spends in the queue before the operation is processed. This value represents the queue time for receive operations that are issued from other nodes that are in the local cluster.
Overall Port to Local Node Queue Time (ms/op): The average number of milliseconds that a send or receive operation spends in the queue before the operation is processed. This value is for send and receive operations that are issued between the component and other nodes that are in the local cluster.
Port to Remote Node Send Response Time (ms/op): The average number of milliseconds to complete a send operation to a node that is in the remote cluster. This value represents the external response time of the transfers.
Port to Remote Node Receive Response Time (ms/op): The average number of milliseconds to complete a receive operation from a node that is in the remote cluster. This value represents the external response time of the transfers.
Overall Port to Remote Node Response Time (ms/op): The average number of milliseconds to complete a send operation to, or a receive operation from a node in the remote cluster. This value represents the external response time of the transfers.
Port to Remote Node Send Queue Time (ms/op): The average time in milliseconds that a send operation spends in the queue before the operation is processed. This value represents the queue time for send operations that are issued to a node that is in the remote cluster.
Port to Remote Node Receive Queue Time (ms/op): The average time in milliseconds that a receive operation spends in the queue before the operation is processed. This value represents the queue time for receive operations that are issued from a node that is in the remote cluster.
Overall Port to Remote Node Queue Time (ms/op): The average number of milliseconds that a send or receive operation spends in the queue before the operation is processed. This value is for send and receive operations that are issued between the component and a node that is in the remote cluster.

Port error data

You can create performance reports that include the following information:

Link Failure Rate (count/s): The average number of miscellaneous fibre channel link errors per second for ports. Link errors might occur when an unexpected Not Operational (NOS) is received or a link state machine failure was detected.
Loss of Sync Rate (count/s): The average number of times per second that the port lost synchronization with its partner port. These types of errors usually indicate physical link problems, caused by faulty SFP modules or cables, or caused by faulty connections at the switch or patch panel. However in some cases this can also occur due to mismatching port speeds between the partner ports, when auto-negotiation of link speed is disabled.; Synchronization is assumed lost after a timeout interval expires.
Loss of Signal Rate (count/s): The average number of times per second at which the port lost communication with its partner port. These types of errors usually indicate physical link problems, caused by faulty SFP modules or cables, or caused by faulty connections at the switch or patch panel. However, in some cases, this error can also occur when the maximum link distance between ports is exceeded, for the type of connecting cable and light source.
CRC Error Rate (count/s): The average number of frames per second that are received in which a cyclic redundancy check (CRC) error is detected. A CRC error is detected when the CRC in the transmitted frame does not match the CRC computed by the receiver. For Brocade switches, this metric includes only the CRC Errors with a good end-of-frame (EOF) indicator.
Primitive Sequence Protocol Error Rate (count/s): The average number of primitive sequence protocol errors per second that are detected.; This error occurs when there is a link failure for a port.
Invalid Transmission Word Rate (count/s): The average number of bit errors per second that are detected.

Volume data

You can create performance reports that include the following information:

Overall Read I/O Rate (ops/s): The average number of read operations per second. This value includes both sequential and nonsequential read operations.
Overall Write I/O Rate (ops/s): The average number of write operations per second. This value includes both sequential and nonsequential write operations.
Total Overall I/O Rate (ops/s): The average number of read operations and write operations per second. This value includes both sequential and nonsequential operations.
Read Data Rate (MiB/s): The average number of MiBs per second that are transferred for read operations.
Write Data Rate (MiB/s): The average number of MiBs per second that are transferred for write operations.
Total Data Rate (MiB/s): The average number of MiB per second that are transferred for read operations and write operations.
Read Response Time (ms/op): The average number of milliseconds to complete a read operation.
Write Response Time (ms/op): The average number of milliseconds to complete a write operation.
Overall Response Time (ms/op): The average number of milliseconds to complete an I/O operation. This value includes both read and write operations.
Read Transfer Size (KiB/op): The average number of KiB that are transferred per read operation.
Write Transfer Size (KiB/op): The average number of KiB that are transferred per write operation.
Overall Transfer Size (KiB/op): The average number of KiB that are transferred per I/O operation. This value includes both read and write operations.

Cache data

You can create performance reports that include the following information:

Write Cache Delay I/O Rate (ops/s): The average number of I/O operations per second that are delayed because of space constraints in the write cache, or because of other conditions.; This value applies only to resources that are running a version of IBM Storage Virtualize earlier than 7.3. The metric is an approximation because actual transfer rates are different for each cache layer. Therefore, you cannot directly compare this metric from resources that are 7.3 or later with earlier versions.
Write Cache Overflow I/O Rate (ops/s): The average number of tracks per second that are written but are delayed because there is not enough space in the write cache. This value applies only to resources that are running a version of IBM Storage Virtualize earlier than 7.3.
Write Cache Flush Through I/O Rate (ops/s): The average number of tracks per second that are written to disk in flush-through mode. This value applies only to resources that are running a version of IBM Storage Virtualize earlier than 7.3.
Write Cache Write Through I/O Rate (ops/s): The average number of tracks per second that are written to disk in write-through mode. This value applies only to resources that are running a version of IBM Storage Virtualize earlier than 7.3.
Overall Read Cache Hit Percentage: The percentage of all read operations that find data in the cache. This value includes both sequential and random read operations, and read operations in the volume cache and volume copy cache where applicable.; You can use this value to understand throughput or response times. Low cache-hit percentages can increase response times because in the event of a cache miss, the data must be read from the back-end storage resources.
Overall Write Cache Hit Percentage: The percentage of all write operations that are handled in the cache. This value includes both sequential and random write operations, and write operations in the volume cache and volume copy cache where applicable.
Total Overall Cache Hit Percentage: The percentage of all read operations and write operations that are handled in the cache. This value includes both sequential and random read and write operations, and read and write operations in the volume cache and volume copy cache where applicable.; You can use this value to understand throughput or response times. Low cache-hit percentages can increase response times because a cache miss requires access to the back-end storage resources.
Disk to Cache Transfer Rate (ops/s): The average number of sectors or tracks per second that are transferred per second from the disks to the cache. This value applies only to resources that are running a version of IBM Storage Virtualize earlier than 7.3. The metric is an approximation because actual transfer rates are different for each cache layer. Therefore, you cannot directly compare this metric from resources that are 7.3 or later with earlier versions.
Cache to Disk Transfer Rate (ops/s): The average number of sectors or tracks per second that are transferred from the cache to the disks. This value applies only to resources that are running a version of IBM Storage Virtualize earlier than 7.3. The metric is an approximation because actual transfer rates are different for each cache layer. Therefore, you cannot directly compare this metric from resources that are 7.3 or later with earlier versions.
Write Cache Delay Percentage: The percentage of I/O operations that are delayed because of space constraints in the write cache, or because of other conditions. The value is a percentage of all operations.; This value applies only to resources that are running a version of IBM Storage Virtualize earlier than 7.3. The metric is an approximation because actual transfer rates are different for each cache layer. Therefore, you cannot directly compare this metric from resources that are 7.3 or later with earlier versions.
Read Ahead Percentage of Cache Hits: The percentage of all read cache hits that occur on pre-staged data. This value applies only to the volume copy cache if the resource is running IBM Storage Virtualize 7.3 or later.
Dirty Write Percentage of Cache Hits: The percentage of all cache write hits that occur on data in the cache that is marked as modified. This value represents how effectively write operations are coalesced before the data is written to disk. This value applies only to resources that are running a version of IBM Storage Virtualize earlier than 7.3.
Write Cache Overflow Percentage: The percentage of write operations that are delayed because there is not enough space in the write cache.
Write Cache Flush Through Percentage: The percentage of tracks that are written to disk in flush-through mode. This value applies only to resources that are running a version of IBM Storage Virtualize earlier than 7.3.
Write Cache Write Through Percentage: The percentage of tracks that are written to disk in write-through mode. This value applies only to resources that are running a version of IBM Storage Virtualize earlier than 7.3.

Back-end array data

You can create performance reports that include the following information:

Back-End Read I/O Rate (ops/s): The average number of read operations per second that are issued to the back-end storage resources.
Back-End Write I/O Rate (ops/s): The average number of write operations per second that are issued to the back-end storage resources.
Total Back-End I/O Rate (ops/s): The average number of I/O operations per second that are transmitted between the back-end storage resources and the component. This value includes both read and write operations.
Back-End Read Data Rate (MiB/s): The average number of MiB per second that are read from the back-end storage resources.
Back-End Write Data Rate (MiB/s): The average number of MiB per second that are written to the back-end storage resources.
Total Back-End Data Rate (MiB/s): The average rate at which data is transmitted between the back-end storage resources and the component. The rate is measured in MiB per second and includes both read and write operations.
Back-End Read Response Time (ms/op): The average number of milliseconds for the back-end storage resources to respond to a read operation.
Back-End Write Response Time (ms/op): The average number of milliseconds for the back-end storage resources to respond to a write operation.
Overall Back-End Response Time (ms/op): The average number of milliseconds for the back-end storage resources to respond to a read or a write operation.
Peak Back-End Read Response Time (ms): The longest time for a back-end storage resource to respond to a read operation.
Peak Back-End Write Response Time (ms): The longest time for a back-end storage resource to respond to a write operation by a node.
Back-End Read Transfer Size (KiB/op): The average number of KiB that are transferred per read operation from the back-end storage resources.
Back-End Write Transfer Size (KiB/op): The average number of KiB that are transferred per write operation to the back-end storage resources.
Overall Back-End Transfer Size (KiB/op): The average transfer size, in KiB, of a read or a write operation to the back-end storage resources.
Back-End Read Queue Time (ms/op): The average number of milliseconds that a read operation spends in the queue before the operation is sent to the back-end storage resources.
Back-End Write Queue Time (ms/op): The average number of milliseconds that a write operation spends in the queue before the operation is sent to the back-end storage resources.
Overall Back-End Queue Time (ms/op): The average number of milliseconds that a read or a write operation spends in the queue before the operation is sent to the back-end storage resources.
Peak Back-End Read Queue Time (ms): The longest time that a read operation spends in the queue before the operation is sent to the back-end storage resources.
Peak Back-End Write Queue Time (ms): The longest time that a write operation spends in the queue before the operation is sent to the back-end storage resources.

Other data

You can create performance reports that include the following information:

Global Mirror Write I/O Rate (op/s): The average number of write operations per second that are issued to the Global Mirror secondary site.
Global Mirror Overlapping Write I/O Rate (op/s): The average number of overlapping write operations per second that are issued by the Global Mirror primary site. Some overlapping writes are processed in parallel and are excluded from this value.; This value applies to resources that are running IBM Storage Virtualize.
Peak Read Response Time (ms): The worst response time measured for a read operation in the sample interval.
Peak Write Response Time (ms): The worst response time measured for a write operation in the sample interval.
Global Mirror Secondary Write Lag (ms/op): The average number of additional milliseconds that it takes to service each secondary write operation for Global Mirror. This value does not include the time to service the primary write operations.; You monitor the value of Global Mirror Secondary Write Lag to identify delays that occurred during the process of writing data to the secondary site.; Average number of additional milliseconds it took to service each secondary write operation for Global Mirror, beyond the time needed to service the primary writes
Processor Utilization Percentage: The average percentage of time that the processors on nodes are busy doing system I/O tasks. This value applies only to resources that are running IBM Storage Virtualize.
Global Mirror Overlapping Write Percentage: The percentage of overlapping write operations that are issued by the Global Mirror primary site. Some overlapping writes are processed in parallel and are excluded from this value.; Applies to resources that are running IBM Storage Virtualize.
Overall Host Attributed Response Time Percentage: The percentage of the average response time that can be attributed to delays from host systems. This value includes both read response times and write response times, and can help you diagnose slow hosts and fabrics that are not working efficiently.; For read response time, the value is based on the time that it takes for hosts to respond to transfer-ready notifications from the nodes. For write response time, the value is based on the time that it takes for hosts to send the write data after the node responds to a transfer-ready notification.
Zero Buffer-to-Buffer Credit Timer (microseconds): The number of microseconds that the port is not able to send frames between ports because there is insufficient buffer-to-buffer credit.; In Fibre Channel technology, buffer-to-buffer credit is used to control the flow of frames between ports. Buffer-to-buffer credit is measured from the last time that metadata was collected.; If this metric is not available, use the Port Send Delay Time metric instead.
Zero Buffer-to-Buffer Credit Percentage: The amount of time, as a percentage, that the port was not able to send frames between ports because of insufficient buffer-to-buffer credit. The amount of time value is measured from the last time that metadata was collected. In Fibre Channel technology, buffer-to-buffer credit is used to control the flow of frames between ports.