Making alarm in disk space using cloudwatch
Solution 1:
Amazon has provided exactly what you are looking for:
mon-put-instance-data.pl
- Collects system metrics on an Amazon EC2 instance (memory, swap, disk space utilization) and sends them to Amazon CloudWatch.http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/mon-scripts.html
Note: Somebody had posted a pointer to this as an answer here earlier, but it looks like the answer was taken down. I wish they could get credit for this answer.
I'll also pull the aws-missing-tools link from cyberx86's comment above into this answer as it could be helpful:
https://github.com/colinbjohnson/aws-missing-tools/blob/master/ec2-write-storage-used/ec2-write-storage-used.sh
Solution 2:
Amazon doesn't have any visibility into the state of your filesystems.
As such, you'll need to write your own script that pushes disk space metrics into a CW custom metric.