Can you monitor OSDisk freespace instead of OSDisk IOPs of Azure VM running windows?

Greetings cloudworxs and tommykneetz 

As per my understanding the Perf table is related to Log Analytics using MMA (Microsoft Monitoring Agent) and InsightMetrics is the table used by AMA (Azure Monitoring Agent).

I don't know if it is by design but I assume it is because by the moment I removed MMA and my queries stopped working the only way to have everything back using AMA was to use InsightMetrics table. I didn't find anywhere the accuracy of my assumption so I took it for granted.

That said, here it is something you can try to achieve your results:

• Using FreeSpaceMB which returns the Free Space of your machines in MB

InsightsMetrics
| where Namespace == "LogicalDisk" and Name == "FreeSpaceMB"

• Using FreeSpacePercentage which returns the free space in %

InsightsMetrics
| where Namespace == "LogicalDisk" and Name == "FreeSpacePercentage"

Cheers...