Hi. On Tue, Oct 23, 2018 at 01:40:57PM +0200, Steve Keller wrote: > Debian uses some long (more than 8 chars) user and group names which I > don't particularly like, e.g. > > systemd-timesync > systemd-network > Debian-exim > messagebus > telnetd-ssl > > This is annoying with ps(1) which abbreviates these names. For more > than 20 years I have always limited user names to 8 chars on all my > Unix and Unix-like systems. Can I rename Debian's user names without > problems or will they be re-created by apt the next time I install or > upgrade an affected package?
In short - no. Such users are created by packages' postinst scripts, and postinst scripts are called on each package upgrade. > Also, I wonder why I have user names like Debian-exim in my > /etc/passwd although I haven't installed exim. It was part of the > initial install but I have removed it afterwards. Shouldn't the > package management remove those user entries, too? It can happen for some packages and it won't happen for the other. Depends on whenever package's maintainer put an appropriate 'userdel <foo>' in postrm script. > May I remove it by hand? As long as you don't have any package that's name starts with exim4 installed - sure. Should not break anything. > Next, there are many names which are both, a user name and a group > name. However, I don't like that many of these don't have the same > numeric uid and gid. Are these IDs fixed in Debian or may I renumber > them to my liking? They only fix uids and gids if their number do not exceed 100, for compatibility with other distributions/OSes. These users, while seemingly 'system' ones, use random uids/gids. Changing these gids/uids come with the usual caveat - don't forget to change uids/gids for any filesystem objects (files, dirs, pipes, sockets etc) that belonged to original gids/uids. Reco
