AWS Cloudwatch disk metrics showing values as zero

Question

The Cloudwatch disk metrics values of EC2 instance that is causing problems, there are no data. I am using C4.xlarge instance and the root device type is EBS. In Cloudwatch following metrics are shown as zero,

• Disk Reads(Bytes)
• Disk Read Operations
• Disk Writes(Bytes)
• Disk Write Operations

The Minimum,Maximum,Average and Sum of the above items are zero.

Network and CPU monitors return data fine.

Any idea why ?

Thanks,

Answer 1

Those metrics are not for EBS volumes, they are for instance store volumes, which the C4 class doesn't have.

For EBS volumes, see the metrics for the individual volumes.