Fstab file is one of the most
important file in linux. The main use is that it maps devices to locations so
that devices can be used. It contains information of all the partitions and
storage devices in your computer. We need to have root privileges for modifying
the file.
A basic structure and some
contents of the file will look like this,
|
Device
/ root
/home
swap
|
mount_location
/
/home
swap
|
fileSystem
ext3
ext3
ext3
|
Options
default
rw,suid,dev,noexec,auto,nouser,async
default
|
Dump
1
1
0
|
Fsck
1
2
0
|
Device is the underlying
device
Mount location, is nothing
but a location where we mounted the file system for accessing.
File System defines the type
of the current file system such as ext3, fat, ext2, ntfs, swap e.t.c.There is a
Special option available called auto which simply means that the file system type is
detected automatically.
Options: these are options
available for a partition. This is the confusing part in the file. If we know
some of the options and what they actually do, it is pretty easy.
auto and noauto With the auto option, the device will be mounted
automatically at boot up and this is the default options. If you don't want the
device to be mounted automatically, we can use noauto. When we use noauto it
will not be available until explicitly mounted.
ro Mount the filesystem read-only.
rw Mount the filesystem read-write
defaults Uses the default options that are rw, suid, dev, exec,
auto, nouser, and async
exec and noexec exec lets you execute binaries that are on that
partition, whereas noexec doesn't let you do that. noexec might
be useful for a partition that contains binaries you don't want to execute on
your system, or that can't even be executed on your system
These are not only the
available ones. There are some more options available.
Dump : the dump is nothing
but a linux utility for taking a
backup.When started dump checks the entry and uses the number to decide if
a file system should be backedup or not
O: dump will ignore the file
system (most cases)
1: dump will back up
Fsck : this reads the number in identifies
in which order the file system check should be done.
0: will not check
1: root
2: other file systems
Happy learning J
