[Borgbackup] Separating repos

[Ed Blackman]

I have a set of systems backing up to a single repository on an internal 
borg server.  Initially all the archives came from the same system, and 
there was a good chance that as files moved around in that system that 
they'd be backed up in one set of archives, then show up in another.  So 
I used a single repository to maximize deduplication.

Over time, I've separated the functions of that single system into 
multiple systems, and also improved procedures so that a given file 
should show up in at most one type of archive.  But since they're going 
into a shared repo, the backups have to spend time syncing the cache.

I'd like to separate retain the archives but separate them into 
different repos, but it doesn't look like borg has a native way to copy 
archives from one repo to another.

Is the only way to do it to make a copy of the repo directory outside of 
borg, and then selectively remove archives from one copy or the other?  
Would the repos shrink automatically as the archives are removed, such 
that they would approximately sum to the original repo size, less some 
for chunks that are now duplicated in two repos?

-- 
Ed Blackman