Memory metrics are not displayed for Azure Linux VM even after installing Linux Diagnostic extension (LAD).
As per the latest Microsoft documentation, Python 2 needs to be installed on the Linux VM as well as it is a requirement for Linux Diagnostic extension ver. 2.2.x and later.
For more information, please refer to Use Linux diagnostic extension 3.0 to monitor metrics and logs article from Microsoft.
Note: FOG-4337 was logged and the 6.3 and higher documentation has been updated with this requirement.
