[rdiff-backup-users] Force a regression of rdiff-backup archive

[Dominic Raferd]

I have a problem that a repository which 3 days ago occupied 26G has 
mushroomed to 44G. The reason is that one night the backup seems to have 
gone badly wrong, thinking the source data was missing, then the next 
night it was all okay again - so it generated lots of diffs for files 
that had gone and then I guess they all got stored in the clear again 
because they had reappeared as 'new' files. I know that these days 18G 
is not such a big deal but it happens to be a problem for me with my 
present media.

What I would like to do is remove these last few days of backups but 
without losing my earlier backups (which are valuable). The logical 
thing seems to be to force a regression of the backup (twice, say, to 
get back to the state before the first problem occurred), but there does 
not seem to be any way to force this to happen?

Can anyone suggest anything?

Dominic