The sixth column is used by fsck to decide in what order to check filesystems when you boot the system. The root filesystem should have a 1 in this field, filesystems that don’t need to be checked (such as the swap partition) should have a 0, and all other filesystems should have a 2. It’s worth noting that the swap partition isn’t exactly a filesystem in the sense that it does not contain files and directories but is just used by the Linux kernel as secondary memory. However, for historical reasons, the swap partitions are still listed in the same file as the filesystems.
Column four contains one or more options to use when mounting the filesystem. You can check the mount manpage for a summary; see section 5.1 on page [*].
10.2.4 Removable Disks (Floppies, Zip Disks, Etc.)
Add the following lines to your /etc/fstab file:
/dev/sda1 /mnt/zip ext2 noauto,user 0 0
/dev/sda4 /mnt/dos msdos noauto,user 0 0
From now on, you’ll be able to mount the DOS-formatted Zip disks with the command mount /mnt/dos, and you be able to mount Linux-formatted Zip disks with the command mount /mnt/zip.
If you have SCSI hard disks in your system, you’ll have to change sda to sdb or sdc in the example above.
10.3 Backup Tools
Backups are important under any operating system. Debian GNU/Linux provides several different utilities that you might want to use. Additionally, while many of these utilities were aimed at tape backups originally, you’ll find that they are now being used for other things. For instance, tar is being used for distributing programs over the Internet. Some of the utilities that you’ll find include the following:
◼ Taper is a menu-driven, easy-to-learn backup program that can back up to a variety of media. Its limitation is that it doesn’t handle large (4GB or larger) backups.
◼ dump is designed specifically for tapes; its main strengths are its interface for file restores, low-level filesystem backups, and incremental backup scheduling. Its limitations include the inability to back up NFS or other non-ext2 filesystems and some rather arcane defaults.
◼ GNU tar (short for Tape ARchiver) is an implementation of what is probably the most widely used backup or archiving utility in Linux today. It makes a good general purpose tool and can deal with the widest variety of target media. Additionally, many different systems can read tar files, making them highly portable. tar’s weaknesses include a weaker incremental backup system than dump and no interactive restore selection screen.