Performance metrics for Dell EMC storage systems

Monitor the performance metrics that are collected for Unity, VMAX, and VNX storage systems.

Overview

The performance metrics are described in the following sections:
Restriction: For Dell EMC, performance metrics are only available for block storage systems.

Unity storage systems

The following performance metrics are available for Unity resources:

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.

Volume metrics for Unity

Volume performance metrics are divided into the following categories:
Tip: You can view the volume metrics in Key volume metrics for the following resources:
  • Volumes
  • Pools
  • 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 (Overall) The average number of milliseconds to complete an I/O operation. This value includes both read and write operations.
Transfer Size (Read) The average number of KiB that are transferred per read operation.
Transfer Size (Write) The average number of KiB that are transferred per write operation.
Transfer Size (Overall) The average number of KiB that are transferred per I/O operation. This value includes both read and write operations.
Tip: You can view the volume metrics in Cache hit metrics for the following resources:
  • Nodes
  • Storage systems
Table 2. Cache hit metrics
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 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.
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.

Disk metrics for Unity

You can view the metrics in Key disk metrics for the following resources:
  • Pools
  • Disks
  • Nodes
  • Storage systems
Table 3. Key disk metrics
Metric Definition
I/O Rate (Read) The average number of read operations per second that are issued to the back-end storage resources.
I/O Rate (Write) The average number of write operations per second that are issued to the back-end storage resources.
I/O Rate (Total) 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.
Data Rate (Read) The average number of MiB per second that are read from the back-end storage resources.
Data Rate (Write) The average number of MiB per second that are written to the back-end storage resources.
Data Rate (Total) 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.
Response Time (Overall) The average number of milliseconds for the back-end storage resources to respond to a read or a write operation.
Transfer Size (Read) The average number of KiB that are transferred per read operation from the back-end storage resources.
Transfer Size (Write) The average number of KiB that are transferred per write operation to the back-end storage resources.
Transfer Size (Overall) The average transfer size, in KiB, of a read or a write operation to the back-end storage resources.

Port metrics for Unity

You can view the metrics in Key port metrics for ports, nodes, and storage systems.
Table 4. Key port metrics
Metric Description
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 (Receive) The average number of I/O operations per second for operations in which the port receives data.
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 (Send) The average rate at which data is sent from the port. The rate is measured in MiB 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 (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.
Transfer Size (Send) The average number of KiB that are transferred per send operation.
Transfer Size (Receive) The average number of KiB that are transferred per receive operation.
Transfer Size (Overall) The average number of KiB that are transferred per I/O operation. This value includes both send and receive operations.

Node metrics for Unity

You can view the metrics in Key node metrics for nodes and storage systems.
Table 5. Key node metrics
Metric Description
System CPU The average percentage of time that the processors on nodes are busy doing system I/O tasks.

File system metrics for Unity

Unless otherwise noted, you can view the performance metrics in Key file system metrics for the following resources:
  • Pools
  • Nodes
  • File systems
  • Storage systems
Tip: For a storage system, the metrics contain summary values for all of the file systems on the storage system.
Table 6. Key file systems metrics
Metric Definition
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.
Transfer Size (Read) The average number of KiB that are transferred per read operation.
Transfer Size (Write) The average number of KiB that are transferred per write operation.
Transfer Size (Overall) The average number of KiB that are transferred per I/O operation. This value includes both read and write operations.

VMAX storage systems

The following performance metrics are available for VMAX resources:

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.

Volume metrics for VMAX

Volume performance metrics are divided into the following categories:
Tip: Unless otherwise noted, you can view the volume metrics in Key volume metrics, Cache hit metrics, and Transfer size metrics for the following resources:
  • Volumes
  • Directors
  • Storage systems
Table 7. 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)1 The average number of milliseconds to complete a read operation.
Response Time (Write)1 The average number of milliseconds to complete a write operation.
Response Time (Overall)1 The average number of milliseconds to complete an I/O operation. This value includes both read and write operations.
Volume Utilization2 The average percentage of time that the volume is busy.
Normal I/O Rate (Read) The average number of nonsequential read operations per second.
Normal I/O Rate (Write) The average number of nonsequential write operations per second.
Normal I/O Rate (Total) The average number of nonsequential I/O operations per second. This value includes both read and write operations.
Sequential I/O Rate (Read) The average number of sequential read operations per second.
Sequential I/O Rate (Write) The average number of sequential write operations per second.
Sequential I/O Rate (Total) The average number of sequential I/O operations per second. This value includes both read and write operations.
Note:
  1. This metric is only available when you view the performance of volumes or storage systems.
  2. This metric is only available when you view the performance of volumes.
Table 8. Cache hit metrics
Metric Description
Normal I/O Cache Hits (Read) The percentage of nonsequential read operations that find data in the cache. 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.
Normal I/O Cache Hits (Write) The percentage of nonsequential write operations that are handled in the cache.
Normal I/O Cache Hits (Total) The percentage of nonsequential I/O operations that are handled in the cache. This value includes both read and write operations. 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.
Sequential I/O Cache Hits (Read) The percentage of sequential read operations that find data in the cache. 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.
Sequential I/O Cache Hits (Write) The percentage of sequential write operations that are handled in the cache.
Sequential I/O Cache Hits (Total) The percentage of sequential I/O operations that are handled in the cache. This value includes both read and write operations. 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.
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 9. 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.

Disk metrics for VMAX

Disk performance metrics for VMAX block storage systems are divided into the following categories:
Table 10. Key disk metrics
Metric Definition
I/O Rate (Read) The average number of read operations per second that are issued to the back-end storage resources.
I/O Rate (Write) The average number of write operations per second that are issued to the back-end storage resources.
I/O Rate (Total) 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.
Data Rate (Read) The average number of MiB per second that are read from the back-end storage resources.
Data Rate (Write) The average number of MiB per second that are written to the back-end storage resources.
Data Rate (Total) 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.
Response Time (Overall) The average number of milliseconds for the back-end storage resources to respond to a read or a write operation.
Disk Utilization Percentage The approximate utilization percentage of a particular array over a particular time interval, that is, the average percent of time that the disk associated with the array was busy.
Table 11. Transfer size metrics
Metric Description
Transfer Size (Read) The average number of KiB that are transferred per read operation from the back-end storage resources.
Transfer Size (Write) The average number of KiB that are transferred per write operation to the back-end storage resources.
Transfer Size (Overall) The average transfer size, in KiB, of a read or a write operation to the back-end storage resources.

Port metrics for VMAX

You can view the metrics below for ports and storage systems.

Table 12. Port metrics
Metric Description
I/O Rate (Total) The average number of send operations and receive operations 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.
Response Time (Overall) The average number of milliseconds to complete a send or receive operation.
Transfer Size (Overall) The average number of KiB that are transferred per I/O operation. This value includes both send and receive operations.

VNX storage systems

The following performance metrics are available for VNX resources:

Volume metrics for VNX

Volume performance metrics are divided into the following categories:
Tip: Unless otherwise noted, you can view the volume metrics in Key volume metrics and Transfer size metrics for the following resources:
  • Volumes
  • Nodes
  • Storage systems
Table 13. 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.
Table 14. 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.

Disk metrics for VNX

Disk performance metrics for VNX storage systems are divided into the following categories:
Table 15. Key disk metrics
Metric Definition
I/O Rate (Read) The average number of read operations per second that are issued to the back-end storage resources.
I/O Rate (Write) The average number of write operations per second that are issued to the back-end storage resources.
I/O Rate (Total) 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.
Data Rate (Read) The average number of MiB per second that are read from the back-end storage resources.
Data Rate (Write) The average number of MiB per second that are written to the back-end storage resources.
Data Rate (Total) 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.
Table 16. Transfer size metrics
Metric Description
Transfer Size (Read) The average number of KiB that are transferred per read operation from the back-end storage resources.
Transfer Size (Write) The average number of KiB that are transferred per write operation to the back-end storage resources.
Transfer Size (Overall) The average transfer size, in KiB, of a read or a write operation to the back-end storage resources.

Port metrics for VNX

You can view the metrics below for ports and storage systems.

Table 17. Port metrics
Metric Description
I/O Rate (Total) The average number of send operations and receive operations 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.
Transfer Size (Overall) The average number of KiB that are transferred per I/O operation. This value includes both send and receive operations.