But wait a minute. The the computer for this has nearly 1 Terabyte of disk storage! What is going on here? ownCloud is installed in the /var directory tree. In some cases a default install of the host O/S (i.e. Fedora) was performed possibly with out any advanced disk partition planning. For example, if a “desktop default” partitioning scheme was followed, the /home directory would be large, and the /var directory smaller and most likely was installed in the / (root) disk partition with other "system directories". ownCloud reports on the storage statistics of the partition the "data directory" is exists, usually installed in to the /var directory tree. To solve the problem? Put /var in to it's own disk partition, put the ownCloud data directory in a separate disk partition, or allocate more space to the / (root) disk partition. Or the real painful part? Re-install the host O/S with a partition plan (I know, OUCH!).