Performance metrics for other storage systems

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Monitor the performance of storage systems that are managed by SMI-S providers. You collect performance metadata from storage systems that are compliant with SMI-S 1.5 or later. The SMI-S providers can be referred to by various names, such as CIM agent, CIMOM (CIM Object Manager) agent, or SMI-S agent.

Overview

Performance metrics are available for the following resources:

Volume metrics
Port metrics

A performance metric might apply to one or more storage resources. To check which resources the performance metric applies to, see the tips and the table footnotes.

Restriction: For NetApp storage systems managed by SMI-S providers, performance monitoring is supported only for volumes and front-end ports. It is not supported at the storage system level.

Volume metrics

Volume performance metrics are divided into the following categories:

Key volume metrics
Cache hit percentage metrics
Average transfer size metrics

Tip: Unless otherwise noted, you can view the volume metrics in Key volume metrics, Cache hit metrics, and Average transfer size metrics for the following resources:

Volumes
Nodes
Storage systems

Table 1. Key volume metrics
Metric	Description
Overall I/O Rate (Read)	The average number of read operations per second. This value includes both sequential and nonsequential read operations.
Overall I/O Rate (Write)	The average number of write operations per second. This value includes both sequential and nonsequential write operations.
Overall I/O Rate (Total)	The average number of read operations and write operations per second. This value includes both sequential and nonsequential operations.
Data Rate (Read)	The average number of MiBs per second that are transferred for read operations.
Data Rate (Write)	The average number of MiBs per second that are transferred for write operations.
Data Rate (Total)	The average number of MiB per second that are transferred for read operations and write operations.
Response Time (Read)	The average number of milliseconds to complete a read operation.
Response Time (Write)	The average number of milliseconds to complete a write operation.
Response Time (Overall)	The average number of milliseconds to complete an I/O operation. This value includes both read and write operations.
Volume Utilization¹	The average percentage of time that the volume is busy.
Note: This metric is only available when you view the performance of volumes.

Table 2. Cache hit percentages
Metric	Description
Overall I/O Cache Hits (Read)	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 I/O Cache Hits (Write)	The average percentage of all write operations that are handled in the cache, across all volumes on the server. This value includes both sequential and nonsequential write operations.
Overall I/O Cache Hits (Total)	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.

Table 3. Average transfer size metrics
Metric	Description
Average Transfer Size (Read)	The average number of KiB that are transferred per read operation.
Average Transfer Size (Write)	The average number of KiB that are transferred per write operation.
Average Transfer Size (Overall)	The average number of KiB that are transferred per I/O operation. This value includes both read and write operations.

Port metrics

Port performance metrics are divided into the following categories:

Key port metrics
Transfer size metrics

Tip: You can view the port metrics in Key port metrics and Transfer size metrics for ports and storage systems.

Table 4. Key port metrics
Metric	Description
I/O Rate (Receive)	The average number of I/O operations per second for operations in which the port receives data.
I/O Rate (Send)	The average number of I/O operations per second for operations in which data is sent from a port.
I/O Rate (Total)	The average number of send operations and receive operations per second.
Data Rate (Receive)	The average rate at which data is received by the port. The rate is measured in MiB per second.
Data Rate (Send)	The average rate at which data is sent from the port. The rate is measured in MiB per second.
Data Rate (Total)	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.

Table 5. Transfer size metrics
Metric	Description
Average Transfer Size (Receive)	The average number of KiB that are transferred per receive operation.
Average Transfer Size (Send)	The average number of KiB that are transferred per send operation.
Average Transfer Size (Overall)	The average number of KiB that are transferred per I/O operation. This value includes both send and receive operations.