Your Virtual Private Server was configured with several user accounts and user groups that exist to allow specific programs to run. Because these users and groups are used by the system, it is important that you do not make changes to them unless you know what the results of your changes will do.
In order to avoid confusion, we have made the vlistuser command. This command will list only the user accounts you have created, along with disk quota use and the home directory for these users. Any of the system users will not be listed.
The first system user is root. Other important users to be aware of are www, which is the user your Web server runs as, pop, smmsp, and mailnull, which are for your email server, ftp for FTP, and sshd, for SSH.
The following is an example of a default /etc/passwd file. Your server will not function properly without at least these users.
root:*:0:0:Superuser:/root:/bin/csh toor:*:0:0:Bourne-again Superuser:/root: daemon:*:1:1:Owner of many system processes:/root:/sbin/nologin operator:*:2:5:System &:/:/sbin/nologin bin:*:3:7:Binaries Commands and Source:/:/sbin/nologin tty:*:4:65533:Tty Sandbox:/:/sbin/nologin kmem:*:5:65533:KMem Sandbox:/:/sbin/nologin games:*:7:13:Games pseudo-user:/usr/games:/sbin/nologin news:*:8:8:News Subsystem:/:/sbin/nologin man:*:9:9:Mister Man Pages:/usr/share/man:/sbin/nologin ftp:*:21:21:Anonymous FTP User:/ftp:/sbin/nologin sshd:*:22:22:Secure Shell Daemon:/var/empty:/sbin/nologin smmsp:*:25:25:Sendmail Submission User:/var/spool/clientmqueue:/sbin/nologin mailnull:*:26:26:Sendmail Default User:/var/spool/mqueue:/sbin/nologin bind:*:53:53:Bind Sandbox:/:/sbin/nologin cyrus:*:60:60:the cyrus mail server:/nonexistent:/sbin/nologin pop:*:68:6:Post Office Owner:/nonexistent:/sbin/nologin www:*:80:80:World Wide Web Owner:/nonexistent:/sbin/nologin
Many of the system users also have their own groups. Most of these groups do not need any additional users in them. Some groups, however, require a user to be a member of in order to use the services. For more details on groups that require membership for access to services, see User Permissions. The following is an example of an original /etc/group file on a new Virtual Private Server. As with users, you need to have at least these groups for your server to function properly.
wheel:*:0:root daemon:*:1:daemon kmem:*:2:root sys:*:3:root tty:*:4:root operator:*:5:root mail:*:6: bin:*:7: news:*:8: man:*:9: games:*:13: staff:*:20:root ftp:*:21: sshd:*:22: smmsp:*:25: mailnull:*:26: guest:*:31:root bind:*:53: cyrus:*:60: www:*:80: web:*:81: pop:*:82: imap:*:83:
If you have any questions about the purpose of any of these users or groups, please Ask our Support Staff or refer to a UNIX manual.