Practical UNIX

Filesystems

UNIX systems do not have a standard name for physical or logical disk drives. Sometimes they are called slices, volumes, divisions, or partitions. No matter what the disk area is called, an empty filesystem must be created there before it can be used. The term filesystem is standard on all types of UNIX systems. A filesystem is an area on one or more disk drives where files and directories can be created. Before a filesystem can be used, it must be mounted. Most UNIX systems have several mounted filesystems available. If a filesystem becomes full, no more files can be created there, even if other filesystems have available disk space.

The df command shows the mounted filesystems and how many free disk blocks each one has:

$ df -v ...