Using Disks and Other Storage Media

On a clear disk you can seek forever.

When you install or upgrade your system, you need to do a fair amount of work on your disks. You have to make filesystems on your disks so that files can be stored on them and reserve space for the different parts of your system.

This chapter explains all these initial activities. Usually, once you get your system set up, you won't have to go through the work again, except for using floppies. You'll need to come back to this chapter if you add a new disk or want to fine-tune your disk usage.

The basic tasks in administering disks are:

• Format your disk. This does various things to prepare it for use, such as checking for bad sectors. (Formatting is nowadays not necessary for most hard disks.)
• Partition a hard disk, if you want to use it for several activities that aren't supposed to interfere with one another. One reason for partitioning is to store different operating systems on the same disk. Another reason is to keep user files separate from system files, which simplifies back-ups and helps protect the system files from corruption.
• Make a filesystem (of a suitable type) on each disk or partition. The disk means nothing to Linux until you make a filesystem; then files can be created and accessed on it.
• Mount different filesystems to form a single tree structure, either automatically, or manually as needed. (Manually mounted filesystems usually need to be unmounted manually as well.)

Chapter 4 contains information about virtual memory and disk caching, of which you also need to be aware when using disks.

This chapter explains what you need to know for hard disks, floppies, CD-ROM's, and tape drives.

 
• Two kinds of devices
• Hard disks
• Floppies
• CD-ROM's
• Tapes
• Formatting
• Partitions
  • The MBR, boot sectors and partition table
  • Extended and logical partitions
  • Partition types
  • Partitioning a hard disk
  • Device files and partitions
• Filesystems
  • What are filesystems?
  • Filesystems galore
  • Which filesystem should be used?
  • Creating a filesystem
  • Mounting and unmounting
  • Checking filesystem integrity with fsck
  • Checking for disk errors with badblocks
  • Fighting fragmentation
  • Other tools for all filesystems
  • Other tools for the ext2 filesystem
• Disks without filesystems
• Allocating disk space
  • Partitioning schemes
  • Space requirements
  • Examples of hard disk allocation
  • Adding more disk space for Linux
  • Tips for saving disk space