VMware {code} Community
dzli
Contributor
Contributor
Jump to solution

Incorrect VirtualDisk.NumberWriteAveraged from QueryAvailableMetric

I've recently been looking over some of the data collected by QueryAvailablePerfMetrics, and I came across some inconsistent data regarding the Disk Write IO metrics, specifically for Virtual Disks - "virtualdisk.numberwriteaveraged.average" 

I'm seeing values 50-100x what I see in vCenter - I see around 120 max in the performance graph for virtual disks (customized to show number write average) when doing a test of writing from /dev/random to a file, but the API reports 12000+ (not exactly 100x). Interestingly enough, when I do a iostat on the VM and monitor write rate, I don't see it going past 30, which makes me wonder what these numbers mean.

I'm calling the API (https://pubs.vmware.com/vi3/sdk/ReferenceGuide/vim.PerformanceManager.html#queryAvailableMetric) using entity = a VM MOR, start time = current time - 1hr, end time = 1hr, interval = PerformanceManagerSummary::getRefreshRate (https://www.vmware.com/support/developer/converter-sdk/conv61_apireference/vim.PerformanceManager.Pr...)

 

Am I calling the API wrong? Or just misunderstanding the metrics?

Reply
0 Kudos
1 Solution

Accepted Solutions
_vladi_
VMware Employee
VMware Employee
Jump to solution

Hi,

This forum is dedicated to the vSphere Client SDK and APIs. I believe you would get better advice if you post it in the vSphere Management SDK (Web Services SDK) forum where the questions for the mentioned APIs belong.

Cheers,

Vladi

View solution in original post

Reply
0 Kudos
2 Replies
_vladi_
VMware Employee
VMware Employee
Jump to solution

Hi,

This forum is dedicated to the vSphere Client SDK and APIs. I believe you would get better advice if you post it in the vSphere Management SDK (Web Services SDK) forum where the questions for the mentioned APIs belong.

Cheers,

Vladi

Reply
0 Kudos
dzli
Contributor
Contributor
Jump to solution

Thanks for pointing that out, I'll repost in the other forum

Reply
0 Kudos