doc: FAQ entries about log file

[buhtz]

Add two FAQ entries about the location of log files and how to read them.

Related to #1643

[buhtz]

Thanks for review. I'll wait for feedback from @ceperman .

[ceperman]

Yes, that's great thanks. It looks like syslog contains the info I was asking for, and the faq describes how to find it - for me:
journalctl --grep backintime

It also shows, by absence of logging, when BIT didn't run when one might have expected it to, which is also very helpful. I thought BIT used anacron (old info in internet says it does) but that's obviously changed and the current docs makes it clear that it doesn't, so if the computer is switched off at the scheduled time, the backup doesn't get taken. My problem. RTFM!

[buhtz]

Thanks for your feedback. Please let us know if you see more aspects for improvement in the docs. Don't hasitate to open multiple issues for this or sending an email to the mailing list.

I thought BIT used anacron (old info in internet says it does) but that's obviously changed

Myself I am not sure if it was that way in that past. But currently BIT try to Imitate an anacron-like behavior. Maybe that is the reason why some people think anacron is involved. How the scheduling works is described here in the (quite out-dated) docs. The scheduling option "Repeatedly (anacron)" is not anacron but just a simple cronjob starting BIT every 15 minutes.

It is on my list to improve that scheduling section to make it more clear to users what is going on. See #1449

[ceperman]

Thanks. I had not noticed that "Repeatedly (anacron)" was a scheduling option - I'd assumed it was a checkbox option that's missing from my oldish Linux Mint distribution version. Again RTFM!