Summary

Running a server within a chroot jail can be a useful security precaution for many server types, and especially for those that don't need access to most files on the computer. Setting up the server requires creating a partial duplicate of the regular Linux directory tree, possibly including the server's executable file itself. You must then either activate a server-specific configuration option to have it lock itself into the chroot jail, or run the server with the chroot command. In either case, the server then operates from within the chroot jail as if the directory you set up were the root directory of the computer, thus limiting the potential for damage the server can do if it's compromised. Doing all of this requires some digging into a server's normal requirements for support files and programs, copying files, and modifying startup procedures so that the server runs in its chroot jail whenever appropriate. You must also be sure to maintain the chroot environment so that it continues to operate as you intend.