Re: Queries resulting from first use of Tarsnap

[Colin Percival <cperciva@tarsnap.com>]

On 04/04/14 09:45, jg5 wrote:
> 1).  After the first backup session had (apparently) been running for several
> hours, I noticed the following message in the terminal window:
> 
> tarsnap: Error looking up betatest-server.tarsnap.com: Name or service not known
> tarsnap: Using cached DNS lookup
> 
> Does anyone know what that means?  Did something go wrong?

Your internet connection glitched.  Tarsnap's connection to the server died, and
it tried to perform another DNS lookup in case the server had changed addresses;
that DNS lookup failed (due to said glitchy internet connection) so tarsnap used
the result of the previous DNS lookup.  If you didn't see any more errors after
this it means that your connection recovered within a few seconds.

Nothing to worry about.

> 2).  How do you know that tarsnap actually *is* running OK?  All I see in the
> terminal window is a blinking cursor.  Apart from that, I don't know if the
> process is running correctly, if it has hung up or what.  It would be nice to
> have some information about what's happening.

Tarsnap, like all good UNIX software, operates quietly unless it has something
important to warn you about or you tell it to be noisy.  You probably want to
add the -v option to the command line, which will have tarsnap report every file
it archives.

> 3).  I've been running the backup every evening for almost a week now for about
> 6 -7 hours at a stretch, but there's no sign that it's getting near completion. 
> Is there any way to get some kind of progress report on a backup using Tarsnap? 
> Something like how much data has been backed up, how much remains to be backed
> up, that kind of thing.  At present, I don't know if my backup will be completed
> tomorrow, next week or next year. It would be nice to have a backup status report.

Tarsnap has no concept of "near completion" because it doesn't know how much
data you have until it finishes chewing through it.  But if you use tarsnap's
--print-stats option then you'll be able to see how much data tarsnap has
archived when it exits.

> 4).  I'm trying to backup my home directory over several sessions, as I can't
> leave the computer running indefinitely.  Therefore, I would expect to see a
> *.part archive after every backup session.  At present, I would expect to see 
> five *.part archives (from 29th March to 2nd April), but so far, can only see
> three (29th - 31st March).  Can anyone suggest why the *.part archives from 1st
> and 2nd April are missing?

How are you stopping Tarsnap?  If you're using ^C then you'll lose progress back
to the last checkpoint it created; hitting ^Q to tell tarsnap to exit cleanly
will ensure that it creates a truncated archive before it exits.

-- 
Colin Percival
Security Officer Emeritus, FreeBSD | The power to serve
Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid