12.09.25, 15:50 +0200, Vincent Lefevre: > On 2025-09-12 14:22:34 +0200, Markus Schönhaber wrote: >> If you just want to see all "mail-related" messages with journalctl, you >> can use >> >> $ journalctl --facility mail > > Indeed, thanks a lot! > >> That doesn't help with journalctl's slowness if the journal has grown >> big, of course. > > It actually helps *very much*. > > joooj% time journalctl -b --facility mail > /dev/null > journalctl -b --facility mail > /dev/null 1.24s user 0.13s system 84% cpu > 1.616 total > joooj% time journalctl -b -u postfix\* > /dev/null > journalctl -b -u postfix\* > /dev/null 3.79s user 28.51s system 26% cpu > 2:02.46 total > > So "--facility mail" is here 75 times as fast as "-u postfix\*".
Good to know - and thanks for measuring! I remembered differently. And since I tend to make sure that the journal doesn't grow too big nowadays, I didn't expect a noticeable difference on my machines. Should have checked before presenting something as a fact, though... -- Regards mks
