Verify storage configuration
- davg – this is the average response time for a command being sent to the device.
- kavg – this is the average response time a command is in the vmkernel
- gavg – this is the response time as it appears to the VM. Usually davg + kavg.
- CMD/s – number of IOps being sent to or received from the device or the VM.
If you experience high latency times, (davg/kavg) then its probably best to investigate issues with your array and/or switches and paths to the array. VMware makes the following recommendations to solve storage contention issues.
- Check the CPU usage of the VMs and increase queue depth (advanced setting) if needed.
- Storage vMotion the VM or VMs to a new LUN with more spindles or add more disks to the LUN in question.
- Increase the VMs memory – this will allow for more OS caching which may reduce I/O activity.
- defragment file systems
- Turn off any anti-virus on-demand scans.
Troubleshoot storage over-commitment issues
- If using it as a boot device, the adapter is enabled automatically. Meaning if you disable it after you have booted, it will be re-enabled next boot.
- By default, the software adapter is disabled and needs to be activated.
- Software (and dependent hardware) adapters utilize vmkernel networking. Thus, you must have the proper settings configured on a vmkernel port to use the adapter properly. You can check a ping through a vmkernel port by using vmkping -D from the command line.
- IF you are using more than one uplink and using different vSS's, then both the IPs need to be on different IP Subnets.
- If using multiple uplinks on one vSS, then each vmkernel port group must map to a different uplink.