Monitoring Free Disk Space and Inodes
A read/write filesystem isn’t much good if it grows to the point where it won’t accept any more files. This could happen if the filesystem fills to capacity or runs out of inodes.
Inodes are the data structures within filesystems that describe files on disk. Every filesystem contains a finite number of inodes, set when the filesystem is created. This number is also the maximum number of files that the filesystem can accommodate. Because filesystems are created with a huge number of inodes, you’ll probably never create as many files as it would take to run out of inodes. However, it is possible to run out of inodes if a partition contains many small files.
It is important to prevent space and inode shortages from occurring on system partitions. The df command gives you the information you need on the status of both disk space utilization and inode utilization.