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Table Of Contents
Average Read Latency per Virtual Machine Disk
This chart displays the top ten virtual machine disks with the highest average read latency in milliseconds.
Data is not displayed when the virtual machine is powered off.
This chart is located in the Performance view of the datastore Performance tab. The counter can also
be displayed for datastore cluster charts.
Table 139. Data Counters
Chart Label Description
Average Read Latency
per Virtual Machine Disk
Latency measures the time used to process a SCSI command issued by the guest OS to the virtual
machine. The kernel latency is the time VMkernel takes to process an I/O request. The device latency
is the time it takes the hardware to handle the request.
Total latency = kernelLatency + deviceLatency.
n
Counter: totalReadLatency
n
Stats Type: Absolute
n
Unit: Milliseconds (ms)
n
Rollup Type: Average
n
Collection Level: 3
Average Write Latency per Virtual Machine Disk
This chart displays the top ten virtual machine disks with the highest average write latency in
milliseconds. Data is not displayed when the virtual machine is powered off.
This chart is located in the Performance view of the datastore Performance tab. The counter can also
be displayed for datastore cluster charts.
Table 140. Data Counters
Chart Label Description
Average Write Latency
per Virtual Machine Disk
Latency measures the time used to process a SCSI command issued by the guest OS to the virtual
machine. The kernel latency is the time VMkernel takes to process an I/O request. The device latency
is the time it takes the hardware to handle the request.
Total latency = kernelLatency + deviceLatency.
n
Counter: totalWriteLatency
n
Stats Type: Absolute
n
Unit: Milliseconds (ms)
n
Rollup Type: Average
n
Collection Level: 3
Read IOPs per Virtual Machine Disk
This chart displays the top ten virtual machines with the highest number of read operations. Data is not
displayed when the virtual machine is powered off.
This chart is located in the Performance view of the datastore Performance tab. The counter can also
be displayed for datastore cluster charts.
vSphere Monitoring and Performance
VMware, Inc. 38