Running Linux, Third Edition

Chapter 6. Managing Filesystems, Swap, and Devices

You probably created filesystems and swap space when you first installed Linux (most distributions help you do the basics). Here is a chance to fine-tune these resources. Most of the time, you do these things shortly after installing your operating system, before you start loading up your disks with fun stuff. But occasionally you will want to change a running system, in order to add a new device or perhaps upgrade the swap space when you upgrade your RAM.

Managing Filesystems

To Unix systems, a filesystem is some device (such as a hard drive, floppy, or CD-ROM) that is formatted to store files. Filesystems can be found on hard drives, floppies, CD-ROMs, and other storage media that permit random access. (Note: a tape allows only sequential access, and therefore can’t contain a filesystem per se.)

The exact format and means by which files are stored is not important; the system provides a common interface for all filesystem types it recognizes. Under Linux, filesystem types include the Second Extended filesystem, or ext2fs, which you probably use to store Linux files; the MS-DOS filesystem, which allows files on MS-DOS partitions and floppies to be accessed under Linux; and several others, including the ISO 9660 filesystem used by CD-ROM.

Each of these filesystem types has a very different underlying format for storing data. However, when you access any filesystem under Linux, the system presents the data as files arranged into ...