VMware Guest memory latency

pgodwin

Does anyone know what the VMware "Guest memory latency" metric actually measures (or where I can see this stat in vSphere?).

We have a have a VM running on a host without any memory contention but am seeing figures in SQL Monitor in the 20-40% range.

Sujay

Hi Peter,

Thank you for your forum post.
The Guest Memory latency measures the percentage of time that the virtual machine had to wait on memory due to it being swapped, compressed or ballooned.

More information is available in the section Memory Metrics for Host System Metrics of https://docs.vmware.com/en/vRealize-Operations-Manager/8.3/com.vmware.vcom.core.doc/GUID-C3CAAE15-2E83-431F-8F2D-C5297A3B6EA9.html 

I hope this information helps.

Regards,
Sujay

pgodwin

Thanks Sujay

To confirm this should be the `Mem|Latency` figure? "Latency Percentage of time the VM is waiting to access swapped or compressed memory."

If so this seems to be the Page-fault latency figure in vSphere. The figures there don't match what is being reported in Redgate. Eg I see figures of ~5% in Redgate, but 0 in vSphere.

Sujay

Hi Peter,

To confirm this should be the `Mem|Latency` figure? "Latency Percentage of time the VM is waiting to access swapped or compressed memory."
The above seems to be correct.

For the mismatch that you are seeing, I have created a support ticket with reference #248986.

Regards,
Sujay