My debian systems start at 100 and allocate upwards. IIRC there was an old system of static per-package UID assignments, but as of Debian 6.0 they appear to be dynamically assigned when you install packages. The highest UID I have is 116. (Apparently I don't install very many daemon packages.)
Regular user accounts start at 1000 on both Debian and Ubuntu. As someone else observed, /etc/login.defs provides the answers: % egrep '[GU]ID' /etc/login.defs UID_MIN 1000 UID_MAX 60000 #SYS_UID_MIN 100 #SYS_UID_MAX 999 GID_MIN 1000 GID_MAX 60000 #SYS_GID_MIN 100 #SYS_GID_MAX 999 -andy
