Re: Is there a way to get a different return-code when incremental backup didn't actually find a difference?

Hi Denis!

Typical situation when somebody helps and receives an even greater help in
exchange :-)
I didn't know about the Tslice feature which is super!!! Much-much easier
and usable :-) Well, there is hardly anything dar can't do... :-) (If it
would be able to backup running VMware virtual machines in an incremental
way perhaps (like Veeam)... :-)))), but that is absolutely another story,
that is not what dar is for obviously and we like it that way... :-))

Thanks very much! And BTW the survey is a good idea if you get there once,
I am sure you would be surprised by the answers :-)

Cheers,
Daniel


Denis Corbin <[email protected]> ezt írta (időpont: 2021. okt. 11., H,
19:42):

> On 11/10/2021 15:36, Daniel wrote:
> > Hi Joost!
> >
> > I have a few ideas, but the answer will not be too professional, sorry
> > bout that :-):
>
> Nice list of pointers, thanks Daniel!
>
> >
> > 1. When running dar, you can direct the output to a file, for instance:
> > dar ... > /backup/date.log
> > This file contains lines that start with "Adding file" or "Adding
> > folder" and that is what exactly means there has been changes (besides
> > perhaps permission-changes, that might be with other strings).
> > If there is no change, then there are none of the strings above in the
> > file which can be checked easily with a grep and after you can easily
> > delete the archive created with no data.
> >
> > 2. You can use -T option aswell to get info about what was archived with
> > minimal scripting.
>
> yep, you have also -Txml to parse XML output. XML output is a more
> stable dar output over time, from dar version to dar version.
>
> >
> > 2. We got here the option "-d" which diffs the archive and the place to
> > be backed up. You can use this option to tell before backing up if it
> > will save anything (simple greps and scripting again).
> >
> > 3. Usualy stroage costs less than retrieval, so if that is the case, you
> > must know that when in need of specific files or dirs, the log file you
> > can create in my "1." above can be used to tell which archive contains
> > the most recent version of the file for instance. Directories can be a
> > bit more problematic because of lot of files, but you can tell when
> > anything was archived in that dir and which archive contains it.
> > Also you can use the command that Denis gave us few years ago to even
> > tell which slice contains the file or dir that needs to be retrieved:
> > "./dar -t /path/to/backup/with/backuparchive -al -E "touch %b.%N.%e" -g
> > etc/xml/xml-core.xml | sed -rn -e 's/.*\s+(.*\.[0-9]+.dar) has a bad or
> > corrupted.*/\1/p'"
>
> There is a more simple way to do the same, since release 2.5.0:
>
> dar -l <backup> -g some/relative/path/to/file -Tslice
> or more widely:
> dar -l <backup> -Tslice
>
> <backup> as always can be replaced by an isolated catalogue, so you
> don't have to fetch anyting from a cold storage at the cost of storing
> the isolated catalogues locally.
>
> By the way, the use of an isolated catalogue also applies to restoration
> (see -A with -x option)
>
> > (you can search for this in the forum)
> > Actually I have created a good method with the above (100% thanks to
> > Denis of course) to minimize costs when using Azure cold storage where
> > the retrieval costs tons compared to storage :-)
> >
> > Hope I helped anything... :-)
>
> It helped me at least :) thanks!
>
> >
> > Regards,
> > Daniel
> >
>
> Cheers,
> Denis
>
>