On Wed 30 Sep 2026 at 10:53:38 (-0400), Stefan Monnier wrote: > > What's the 'right' way to set a system's domain name permanenty (i.e. > > doesn't get lost when you reboot) on Debian systems? > > Over the years, I've grown to realize tat this is fundamentally > ill-defined: the domain name is the way to find the IP address of a host > you want to connect to. The machine itself doesn't necessarily > have/need/use that info: some machines don't have any domain name, some > have several, the domain name(s) can change without the machine being > told, ...
I don't understand not having any domain name. Surely the hostname is a domain name in itself. I ran my network for years like that, and exim (as set up by Debian) would moan about the lack of a dot in /etc/mailname. I only added .corp when I found that there was semi-official documentation for using that. I chose it in preference to .home and .mail merely because grepping -r '\<corp\>' /etc produced fewest false positives. Current false positives here are: home: 173 mail: 162 corp: 0 I haven't yet bothered to move to .home.arpa. Maybe sometime. > IME, most cases where a piece of software wanted to know "the host's > domain name" it was either "wrong" (it didn't actually need to know) or > it could use any "unique enough" name. So it might be worth digging > further into your problem to see if you can push it elsewhere: instead > of "set[ting] the system's domain name", make sure the software > doesn't need that domain name. Doesn't it pay to have a backstop? Cheers, David.
