[Borgbackup] first backup of large amounts

[Thomas Waldmann]

> The server shall be taken offline during backup 1. to prevent files 
> changed,

You could consider your first loooong backups "dirty" and just not care 
about that.

After you transferred most data and things are going quicker, you could 
start with "clean" backups. And after the first clean backup has 
finished successfully, delete the dirty ones.

> 2. for security reasons.

Whatever that means?

> Thx. As far as I understand, these checkpoints are created by default, 
> and setting intervals is optional to adapt it to individual preferences 
> -right?

Yes.

> So if borg --create is stopped (killed?) during backing up 
> files, the next time it is invoked it just checks hashes up to the last 
> checkpoint, what is very fast, and then continues the normal way until 
> it ends or is stopped again.

That's not how it works.

borg never transfers chunks it already has in the repo, that's all.
it knows the hashes of all chunks it already has in the repo (via chunks 
index and repo index).

> Thus, I could simply start borg --create at 
> night, stop it after 6 hours, and repeat this every night until it got 
> all files (return code = 0).

Correct. The return code might as well be 1 (warning), which means that 
you have to check the logs. rc 2 would be an error.