Hi @srinivasarao_as ,
you will need to create that OneAgent extension yourself. You probably have a very distinct usecase for showing per file disk usage (size).
Waht exactly do you need?
The size of one specific file? At a given path?
The total disk space consumption of specific file types?
Another option for you would be to inject metrics using the agent local metric ingest interface. This is a rather straight forward method and could be used e.g. from a cron job.