Sangeetha, can you be more specific with your question.
In general Dynatrace (with the OneAgent technology) can be used to diagnose a myriad of issues by providing visibility into infrastructure and transactional parts of your system. There's a variety of use cases on the website which document this as well as on the blog. https://www.dynatrace.com/news/blog/
Yes, this would be possible. If you use Ansible for example, you could use the
Integration for Problem Notification.
Or you could write a small web serivce, which recives the problem notifications via a custom web hook. Then parse the problems and if it is a filesystem full problem, kick off a script from there.
Just a quick note - there is no option to execute anything on monitored systems via Oneagent. That in contrast with classical monitoring tools. You are just left with the options @Patrick H. mentions.