[systemd-devel] Online backup API for systemd-journal?

[Etienne Doms]

Oh, I knew I was missing something with the "-o export", I wasn't
aware of systemd-journal-remote.

Thanks!

Le lun. 4 sept. 2023 à 18:54, Mantas Mikulėnas <grawity at gmail.com> a écrit :
>
> On Mon, Sep 4, 2023 at 5:35 PM Etienne Doms <etienne.doms at gmail.com> wrote:
>>
>> Hi,
>>
>> I have some embedded systems in the wild, not connected to anything,
>> on which you can push a button "something went wrong, create a dump".
>> Then later I can fetch the said dump and inspect it.
>>
>> I'd like to include the whole journal, for the current boot, in a
>> binary format so that I can later do "journalctl --file
>> path/to/journal-dump.bin" from another machine. I understand that
>> internally everything is stored in /var/log/journal/<machine-id>, but
>> I guess that I cannot blindly tar/cp the .journal files, since this
>> would be racy.
>>
>> So, is there an API to safely dump a big ".journal" file containing a
>> snapshot of "journalctl -b"? I could not find anything in the
>> documentation, sorry in advance if I missed something obvious.
>
>
> Run `journalctl --rotate` (or send a SIGUSR2). All "rotated" .journal files (containing an '@' in their name) are offline and can be copied.
>
>> For now I just dump it with "-o json" which is fine, but then I cannot
>> feed another journalctl with the given json, and need to do manual
>> filtering.
>
>
> If you dump with `-o export` instead (or convert the JSON to the export format), you can later feed the dump into systemd-journal-remote(8) (which is somewhere in /lib/systemd) to import it back into a .journal file.
>
> --
> Mantas Mikulėnas