# Elastic Observability Engineer course - Fleet server not running **URL:** \ **Category:** Elastic Training\ **Created:** [July 30, 2025, 6:25am UTC](https://discuss.elastic.co/t/elastic-observability-engineer-course-fleet-server-not-running/380580 "2025-07-30T06:25:32Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![John\_Sc](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/john_sc/32/140043_2.png) [@John\_Sc](https://discuss.elastic.co/u/John_Sc)\ **Post date:** [July 30, 2025, 7:35am UTC](https://discuss.elastic.co/t/elastic-observability-engineer-course-fleet-server-not-running/380580/2 "2025-07-30T07:35:05Z")
I tried to check if a fleet proces is already running: > [@Lab 2.1 - Elastic Agent - Adding Nginx Integration/Agent fail](https://discuss.elastic.co/t/lab-2-1-elastic-agent-adding-nginx-integration-agent-fail/380490/2): > > Hello @fabio.iovine From the error "{"file.name":"cmd/enroll\_cmd.go","file.line":806},"message":"Fleet Server - Error - listen tcp 0.0.0.0:8220: bind: address already in use","ecs.version":"1.6.0"} Error: fleet-server failed: context canceled" it seems the port is in use, could you please check what is the process which is using the port : sudo lsof -i :8220 If it is related to elastic-agent process of older installation maybe as you have already uninstalled the older agent, you can kill the… This fails because I'm not allowed to use sudo. Also not from a fresh shell. --- _[View the full topic](https://discuss.elastic.co/t/elastic-observability-engineer-course-fleet-server-not-running/380580)._