Creating an ext3 File System

If you are adding a new disk drive to a Linux system and want to utilize the
ext3 file system, you must first partition the hard disk with a program such
as fdisk and then format the file system.
Partitioning with fdisk

To use fdisk, open a shell prompt and log in as the root user. The fdisk command
requires you to specify the device you are partitioning as an argument to the
command. In the following examples, the device will be /dev/hdb, which corresponds
to the second device on the primary IDE channel. To begin, type:

The following table provides the most common fdisk commands.

Table 5-1. fdisk commands

Command What it Does

Tip: If you need to exit the program at any time without altering your disk,
type q.

Now that you are in the fdisk program, type n to create a new partition. The
program will ask you to choose a partition type, choose e for an extended and
p for a primary partition.

Before choosing the partition type, be aware Linux only allows up to four primary
partitions per disk. If you wish to create more than that, one (and only one)
of the four primary poartitions may be an extended partition, which acts as
a container for one or more logical partitions. Since it acts as a container,
the extended partition must be at least as large as the total size of all the
logical partitions it is to contain. For more information on disk partitions,
see the Appendix called An Introduction to Disk Partitions in the Official Linux
Installation Guide.

After choosing the partition type and the number for that partition, choose
which cylinder head you would like the partition to start on. You can type [Enter]
to except the default value.

Next, specify the size. The easiest way to do this is to type +sizeM, where
size is the size of the partition in megabytes. If you press [Enter] without
entering a value, fdisk will use the remainder of the disk.

Repeat this process until you have created your desired partitioning scheme.

Tip: It is a good idea to write down which partitions (for
example, /dev/hdb2) are meant for which file systems (for example, /home/username)
as you create each partition.

Next, you will need to specify what type of file system you intend to put on
the disk because fdisk creates partitions of type unknown by default.

To do this, type t followed by a partition number. Next enter the hex value
for the file system type you intend to install on the partition. For Linux swap
partitions. the hex value is 82. For Linux ext2 or ext3 partitions, the hex
value is 83. For other partition types, use the l command to see a list of file
system types and their hex values. Repeat this for each partition you created.

When you are finished making partitions, type w to save your changes and quit.

Warning: By typing w, you are permanently destroying any data that currently
exists on the device. If you need wish to preserve any data, type q to exit
the program without altering the disk and back up your data.
Formating ext3 File Systems with mkfs

Once you have created partitions on the disk drive using a partitioning program
such as fdisk, you should use mkfs to create an ext3 file system on each partition.

To do this, log in as root and type:

In the above command, replace hdb with the drive letter and X with the partition
number.

Warning

Using mkfs to format a disk partition will permanently destroy any data that
currently exists on the partition.
Assigning a Label with e2label

Once you have created and formated a partition, you should assign it a label
using the e2label command. This allows you to add the partition to /etc/fstab
using a label instead of using a device path, thereby making the system more
robust. [1] To add a label to a partition, type the following command as root:

Where hdb is the drive letter, X is the partition number, and /mount/point
is the mount point you intend to use for the partition.

Once you have assigned each partition a label, add the partitions to /etc/fstab.
To do this, log in as root and type:

Then add a line to /etc/fstab for each labeled partition similar to this:

In the above entry in /etc/fstab, replace each occurrence of /mount/point with
the mount point you intend to use for the partition.

If you need more information on the various options available to you in /etc/fstab,
type man fstab.

If there are partitions whose label you are unsure of, type the following command:

In the above command, replace hdb with the drive letter and X with the partition
number.

This will return something similar to the output below:

Filesystem volume name: /mount/point

In this output, /mount/point is the volume label.

After completing the above steps, you will have successfully added a new ext3
disk to the system. The next section demonstrates how to convert an ext2 disk
partition to an ext3 partition.

This entry was posted on December 7, 2009 at December 7, 2009 and is filed under Linux. You can follow any responses to this entry through the RSS 2.0 feed.