Local Volume Performance Chart

The Disk chart displays historical statistics on disk usage for the selected local volume.

Local Volume Performance Chart

The following table provides information on predefined views and counters.

Chart View

Counter

Measurement Unit

Description

Datastore Usage

Disk/Physical Disk: Disk Read

MB/s

Rate at which data is read from a volume.

Disk/Physical Disk: Disk Write

MB/s

Rate at which data is written to a volume.

Disk/Physical Disk: Disk

MB/s

Sum of read and write rates for a volume.

Datastore Queue Length

Disk/Physical Disk: Avg. Disk Queue Length

Number

Average number of read and write operations queued for a volume.

Datastore IOPS

Disk/Physical Disk: Disk Transfers/sec

Number

Number of read and write operations completed per second, regardless of how much data they involve.

This counter measures disk utilization. If the value exceeds 50, it can be an indicator of a bottleneck.

Datastore Latency

Disk/Physical Disk: Avg Disk sec/Read

Millisecond

Average time that a read operation from a volume takes.

Disk/Physical Disk: Avg Disk sec/Write

Millisecond

Average time that a write operation to a volume takes.