On 03/03/2015 03:33 PM, P. Larry Nelson wrote: > That used to happen in the old days before > system-config-users pretty much kept generated UIDs/GIDs well out > of the range that an installed piece of software might use. > I believe the rule is now that real people users get a UID > 500 > and installed apps (like ntop, UID:103, GID:160) use UIDs < 500, > but I don't know if that's a hard and fast rule with apps or not. > I do the same thing with any local group I create - give it a > GID > 500.
The authoritative source used by useradd (perhaps others) is /etc/login.defs: grep ^UID_MIN /etc/login.defs UID_MIN 500 Historically it was UID >= 500 (note 500 was the first), in recent Fedora's and EL7, it's now 1000: grep ^UID_MIN /etc/login.defs UID_MIN 1000 Note new systems also have min/max values for system accounts in login.defs: # Min/max values for automatic uid selection in useradd # UID_MIN 1000 UID # System accounts SYS_UID SYS_UID_MAX 999
