Chrooted jail allows run command or service such as http / mysql / postfix with special root directory i.e. chroot changes the root directory for application. The biggest benefit is a service that is re-rooted to another directory cannot access files outside that directory. Basically you are going to set service in sandbox. Chrooting offers the following 2 benefits:
[a] Service Isolation
[b] Privilege Separation
But how do you find out if service / server is chrooted or not under Linux?
Simply run ls -ld command on /proc/MAIN-PID/root directory.
For example, find out if httpd chrooted or not:
Run ls command:
ls -ld /proc/23456/root
lrwxrwxrwx 1 root root 0 Sep 10 02:52 /proc/23456/root -> /wwwdata
Find out if postfix is chrooted or not (PID 4645):
ls -ld /proc/4645/root
lrwxrwxrwx 1 root root 0 Sep 10 02:59 /proc/4645/root -> /
The PID 4645 pointing out to / (root) i.e. the root directory for application is not changed or chrooted. This is a quick and dirty way to find out if application is chrooted or not w/o opening configuration files.