Record and solve the cause and process of Nginx failing to start

Today, I encountered a problem that the business of a netizen server could not be opened. It was detected that Nginx could not be started. The specific troubleshooting is as follows.

1. Port conflict:

Check whether other programs are using the ports required by Nginx (the default is 80 or 443 ports). You can try to change the listening port of Nginx. Find the listen command in the Nginx configuration file (usually/etc/nginx/nginx. conf), change the port number to an unoccupied port, and restart Nginx.

2. Configuration file error:

Check whether the configuration file of Nginx has syntax errors. Run the following command in the terminal to check:

 nginx -t

If an error prompt appears, please modify the configuration file according to the prompt and run the above command again to verify the configuration.

3. Permission problem:

Check the permission settings of Nginx related files and directories. Ensure that Nginx has sufficient read and write permissions for configuration files, log files, website root directories, etc. You can try to run Nginx as a superuser (such as root) to troubleshoot the permissions problem.

4. Resource restrictions:

Check the system's resource limits, such as the number of open files and the number of processes. If these limits are too low, Nginx may not start normally. You can improve the resource limit by modifying the limit parameters of the system, such as the corresponding parameters in the/etc/security/limits.conf file.

5. Error log analysis:

Check Nginx's error log file (usually/var/log/nginx/error. log) for more detailed error information. Troubleshoot and solve the corresponding problems according to the prompts in the error log.

If the problem cannot be solved, we simply back up the data and redeploy a new version of Nginx, and change to another version.