We should think about making local copies of the repo to avoid this kind of problems.
A regular Rsync with the repo should be fine. Somebody has an available machine for that?
Backing up a subversion repo using rsync is not fine. If the rsync occurs concurrently with a commit, the produced backup can have inconsistent, corrupt data.
The correct way of backing up a svn repo is using "svnadmin dump", or other similar tools that are aware of svn transactions.