Plesk and Cobalt arranges so that one site can have more than one Unix users associated with it. For example, user1, user2, and user3 are associated with site1. This means:
- there is 'site1' group
- there is user1 user, home=/home/sites/site1/users/user1
- there is user2 user, home=/home/sites/site1/users/user2
- there is user3 user, home=/home/sites/site1/users/user3
- the users belong to group 'site1'
- files and directories under /home/sites/site1 are owned by group 'site1'
- most files and directories under /home/sites/site1 are writtable by group 'site1', so any user can write to them
This scheme enables a site to have several 'team members', each of which has his/her own personal site, along with shell & ftp access.
Other shared webhosting uses simpler scheme, that is, one domain is associated with one Unix user. I've never complaint with this setup, as I like the shorter home directory names (Unix user=site1, home=/home/site1). Easier to remember. And when I want to share or let someone else access my site, I'd just share my password (and change it later when everything is done).
What I wonder is, how many people actually find the Plesk/Cobalt scheme useful.