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 1. 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.

  • Counter: totalWriteLatency
  • Stats Type: Absolute
  • Unit: Milliseconds (ms)
  • Rollup Type: Average
  • Collection Level: 3