Introduction
The file /etc/fstab (it stands for "file system table") contains descriptions of filesystems that you mount often. These filesystems can then be mounted with a shorter command, such as mount /cdrom. You can also configure filesystems to mount automatically when the system boots. You'll probably want to mount all of your hard disk filesystems when you boot.
Example
Look at this file now, by typing more /etc/fstab. It will have two or more entries that were configured automatically when you installed the system. It probably looks something like this:
Code:
# /etc/fstab: static file system information.
/dev/hda1 / ext2 defaults 0 1
/dev/hda3 none swap sw 0 0
proc /proc proc defaults 0 0
/dev/hda5 /tmp ext2 defaults 0 2
/dev/hda6 /home ext2 defaults 0 2
/dev/hda7 /usr ext2 defaults 0 2
/dev/hdc /cdrom iso9660 ro 0 0
/dev/fd0 /floppy auto noauto,sync 0 0
The last three columns may require some explanation.
The fifth column is used by the dump utility to decide when to back up the filesystem.
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 which don't need to be checked (such as the swap partition) should have a 0, and all other filesystems should have a 2.
Column four contains one or more options to use when mounting the filesystem. Here's a brief summary (some of these probably won't make much sense now - they're here for future reference):
async and sync
Do I/O synchronously or asynchronously. Synchronous I/O writes changes to files immediately, while asynchronous I/O may keep data in buffers and write it later, for efficiency reasons.
ro and rw
Mount the filesystem read-only or read-write. If you don't need to make any changes to the filesystem, it's a good idea to mount it read-only so you don't accidentally mess something up. Also, read-only devices (such as CD-ROM drives and floppy disks with write protection tabs) should be mounted read-only.
auto and noauto
When the system boots, or whenever you type mount -a, mount tries to mount all the filesystems listed in /etc/fstab. If you don't want it to automatically mount a filesystem, you should use the noauto option. It's probably a good idea to use noauto with removable media such as floppy disks, because there may or may not be a disk in the drive. You'll want to mount these filesystems manually after you put in a disk.
dev and nodev
Use or ignore device files on this filesystem. You might use nodev if you mount the root directory of another system on your system - you don't want your system to try to use the devices on the other system.
user and nouser
Permit or forbid ordinary users to mount the filesystem. nouser means that only root can mount the filesystem. This is the normal arrangement. You might use the user option to access the floppy drive without having to be root.
exec and noexec
Allow or do not allow the execution of files on this filesystem. Probably you won't need these options.
suid and nosuid
Allow or do not allow the suid bit to take effect. Probably you won't need these options.
defaults
Equivalent to: rw, dev, suid, exec, auto, nouser, async. You can specify defaults followed by other options to override specific aspects of defaults.
fstab Syntax
Code:
[Device] [Mount Point] [File_system] [Options] [dump] [fsck order]
/dev/hdxy or /dev/sdxy.
x will be a letter starting with a, then b,c,....
y will be a number starting with 1, then 2,3,....
Thus hda1 = First partition on the master HD.
