[rdiff-backup-users] Restructuring an archive

[Alan Douglas]

I've been running rdiff-backup for two years, and now desperately need to 
restructure things (this is with version 1.1.15 on Ubuntu).  I've tried 
SplitRdiffBackup but it was taking far too long and really wasn't doing what 
I wanted.  I then wrote a script that would restore each increment in turn 
for the necessary paths, then build a new archive using --current-time, but 
again it was taking far too long.  I've looked at archfs, but computationaly 
speaking, it would be doing the same thing as my script.  

It looks like I'm going to have roll my own solution -- one that applies the 
rdiffs in a more intelligent fashion.  

At least for this first phase, I am working with files from a single 
directory, which keeps it simple.   

My plan is to have a seeding script that will restore back to the oldest 
increment by applying the rdiffs directly using patch, but every ten 
increments would save an intermediate version of the files.  A second script 
would then restore to each increment (adding it to the new archive), by 
applying rdiffs to the closest intermediate version.  

This method should run about 65 times faster than the brute force approach, 
while eating about 200GB for all the intermediate copies.  If I had a couple 
of TBs of spare disk space, it could be done a lot faster and simpler, but I 
don't.  

Has anyone done anything like this before?  Are there any problems or gotchas 
with applying the rdiffs directly, rather than restoring using rdiff-backup?  
Are there any alternatives that I have missed?  I tried searching the list 
archives but it was hard to find good search terms.  

Thanks,
Alan/