Inodes are a data structures that represents file objects in the system. There are some hosting providers which limit inode usage. It is easy to get the five catalogs which most extensively uses up the inodes.
You can do that with an easy query using SSH command line:
for i in `ls -1A`; do echo “`find $i | sort -u | wc -l` $i”; done | sort -rn | head -5
This will outline as a result five catalogs from your current location which uses up most inodes.
You can change the last part head -5 to a different number of results to show.