[systemd-devel] /var/log/journal/

[Lennart Poettering]

On Fri, 05.04.13 22:02, Reindl Harald (h.reindl at thelounge.net) wrote:

> > We have decided to turn on persistancy in F19, and that's done via %post
> > hooks in the RPM.
> > 
> > If you want to turn this off, set Storage=none or Storage=volatile in
> > journald.conf
> 
> great - does F17 and F18 understand the option too to prepare
> any machine under my control and forget the issue?

Yes they should. In the worst case they should just warn about it but go
on.

> what's the exact difference between "none" and "volatile"?

"none" turns off the journal's storage entirely, in which case it is
still highly useful for forwarding all logs from STDOUT/STDERR of the
various daemons to syslog, but won't store anything at all
anymore. "systemctl status" won't show you any log entries in this
case, and "journalctl" will show nothing but a big void.

"volatile" will still allow the journal to log into a small ring buffer
in /run. In this case "systemctl status" and "journalctl" will show a
bit of useful log data still (as on F17, F18), but the logs are quickly
rotated away usually, since /run is relatively small. This means
"systemctl status" might be useful shortly after executing commands on
the service, but that's it.

Lennart

-- 
Lennart Poettering - Red Hat, Inc.