Partitioning Hard Disks

Partitioning a hard disk is a fundamental task when setting up any operating system, and in the Linux world, it offers several practical and performance benefits. Here are some of the reasons for creating multiple partitions on a Linux system:

• Multiple operating systems When Linux is installed alongside an existing Windows OS, each must reside on its own partition. This separation is necessary for both operating systems to function properly, with a boot loader allowing the user to select which OS to boot

• Multiple partitions within an operating system To protect their entire operating system from running out of disk space, people often assign separate partitions to different areas of the Linux filesystem. For example, if /home and /var were assigned to separate partitions, then a gluttonous user who fills up the /home partition wouldn’t prevent logging daemons from continuing to write to log files in the /var/log directory. Multiple partitions also make doing certain kinds of backups (such as an image backup) easier. For example, an image backup of /home would be much faster (and probably more useful) than an image backup of the root filesystem

• Different Filesystem Types Different kinds of filesystems have different structures. Filesystems of different types must be on their own partitions. Also, you might need different filesystems to have different mount options for special features (such as read-only or user quotas). In most Linux systems, you need at least one filesystem type for the root of the filesystem, and one for your swap area. Filesystems on CD-ROM use the iso9660 filesystem type

When you create partitions for Linux, you usually assign the filesystem type as Linux native, using the ext2, ext3,ext4, or xfs type on most Linux systems. If the applications that you are running require particularly long filenames, large file sizes, or many inodes (each file consumes an inode), you may want to choose a different filesystem type

• Special Mount Options The need for specific mount options for security, performance, or functionality reasons may necessitate different partitions. For example, a partition mounted with the noexec option would prevent the execution of binaries, enhancing security. We will explore such options in the Securing Linux section of this gitbook

During installation, systems such as Fedora, RHEL and Ubuntu let you partition your hard disk using graphical partitioning tools.

Understand Different Partition Types

Many Linux distributions give you the option of selecting different partition types when you partition your hard disk during installation. Partition types include the following:

• Linux Partitions Use this option to create a partition for an ext2, ext3, or ext4 filesystem type that is added directly to a partition on your hard disk (or other storage medium). The xfs filesystem type can also be used on a Linux partition. In fact, xfs is now the default filesystem type for RHEL 8 systems

• Logical Volume Manager (LVM) Partitions Create an LVM partition if you plan to create or add to an LVM volume group. LVMs give you more flexibility in growing, shrinking, and moving partitions later than regular partitions do

• RAID Partitions Create two or more RAID partitions to create a RAID array. These partitions should be on separate disks to create an effective RAID array. RAID arrays can help improve performance, reliability, or both as those features relate to reading, writing, and storing your data

• Swap Partitions Create a swap partition to extend the amount of virtual memory available on your system