EC2 Memory and Disk usage Metrics

[matson-itops]

Understand that using nagios plugins to pull memory and disk usage (EBS volumes)
for EC2 instances will result in incorrect data
eg all my ec2 servers show 100% memory use all the time.

can someone help me understand this limitation? Is there some doc w/
clear explanation as to why this happens only on ec2 instances?

I understand that using cloudwatch agents does pull the correct metrics.

[cdienger]

Please clarify which checks are failing by providing a screenshot of the output as well as configuration. I'm not aware(and after doing a quick check with colleagues) of behavior like you're describing.