svn backups

when backing up svn repos using svnadmin dump -r, first i figure out which revision will be dumped, write a log entry and then dump everything up to that specific revision to avoid changes that could have been committed to the repo during that time. it turns out that if one does not specify the range (0:$rev), the dump is created from that revision up to the youngest, not down to rev 0 (docs explicitly say that, but i simply missed that part). which means that with half a dozen branches and a dozen tags a 100M repository produced a 2G dump. loading the dump back into the repo took hours, and it was just one revision and one transaction. half of the time loading would fail quietly altogether, trying to commit that single 2G transaction.

once the bug in the backup scripts has been spotted, the dump is down to 200M (100M compressed) and load time is just a minute or two.