You shouldn’t use root for anything else, other than maintaining your server, so the answer is “normal unix users” always.
Because if you install WordPress as root, and if WordPress is hacked, then it can do anything that a root user can do. It’s like giving your room key, coffer key together with all your valuables to a tenant when giving them a house key.
You are welcome, have a nice day!
More inquiry please..
some plugins need to write files in some wordpress directories such as uploads. it said it could not do so, because the server has no file permissions. this is weird because the directories are owned by the unix user who installed wordpress.
in this case, which unix users actually write files for the plugin?
If you are using Apache web server and want it to user your user account privileges, then you have to install suPHP.
How to install suPHP:
http://www.howtoforge.com/install-suphp-on-various-linux-distributions-for-use-with-ispconfig-2.2.20-and-above
You might also be interesting in a Linux Administration book:
Linux Administration A Beginners Guide
