%general-entities; ]> $LastChangedBy: krejzi $ $Date: 2015-02-10 09:47:02 -0500 (Tue, 10 Feb 2015) $ /etc/passwd /etc/group /etc/login.defs Throughout BLFS, many packages install programs that run as daemons or in some way should have a user or group name assigned. Generally these names are used to map a user ID (uid) or group ID (gid) for system use. Generally the specific uid or gid numbers used by these applications are not significant. The exception of course, is that root has a uid and gid of 0 (zero) that is indeed special. The uid values are stored in /etc/passwd and the gid values are found in /etc/group. Customarily, Unix systems classify users and groups into two categories: system users and regular users. The system users and groups are given low numbers and regular users and groups have numeric values greater than all the system values. The cutoff for these numbers is found in two parameters in the /etc/login.defs configuration file. The default UID_MIN value is 1000 and the default GID_MIN value is 1000. If a specific uid or gid value is not specified when creating a user with useradd or a group with groupadd the values assigned will always be above these cutoff values. Additionally, the Linux Standard Base recommends that system uid and gid values should be below 100. Below is a table of suggested uid/gid values used in BLFS beyond those defined in a base LFS installation. These can be changed as desired, but provide a suggested set of consistent values. Nameuidgidbin 1 lp 9 adm 16atd 1717messagebus1818lpadmin 19named 2020gdm 2121fcron 2222systemd-journal23apache 2525smmsp 2626polkitd 2727rpc 2828exim 3131postfix 3232postdrop 33sendmail34 mail 34vmailman3535news 3636kdm 3737mysql 4040postgres4141dovecot 4242dovenull4343ftp 4545proftpd 4646vsftpd 4747rsyncd 4848sshd 5050stunnel 5151svn 5656svntest 57games 6060kvm 61wireshark 62lightdm 6363sddm 6464scanner 70colord 7171systemd-bus-proxy7272systemd-journal-gateway7373systemd-journal-remote7474systemd-journal-upload7575systemd-network7676systemd-resolve7777systemd-timesync7878ldap 8383avahi 8484avahi-autoipd8585netdev 86ntp 8787unbound 8888plugdev 90anonymous98 nobody 99 nogroup 99 One value that is missing is 65534. This value is customarily assigned to the user nobody and group nogroup and is unnecessary.