How is it possible for a user/group to exceed its quota without owning any files? Here is an extract of my repquota output:
*** Report for group quotas on device /dev/mapper/lata
Block grace time: 15days; Inode grace time: 15days
Space limits File limits
Group used soft hard grace used soft hard grace
----------------------------------------------------------------------
rodrigo +- 26112K 0K 1K 0 0 1
Notice: 0 files, but 26112K space used!
Environment: Ubuntu Trusty (same output on Precise), ocfs2 filesystem.