I recently converted several cvs/svn repositories to git. They ended up being pack based repositories.
Using a few of them on RhodeCode caused no problems. Importing all of them (~300) started causing strange/intermittent errors that seem to resolve if RhodeCode was restarted. Turns out, it is a FD leak.
As RhodeCode is started, and the repository pages are accessed by the web, RhodeCode slowly accumulates .idx and .pack file handles and never closes them (checked using 'lsof -p <pid>').
Workaround: don't use pack based repositories :)