16.16.5. Recommended Partitioning Scheme

Unless you have a reason for doing otherwise, we recommend that you create the following partitions:

A swap partition (at least 256 MB) — swap partitions are used to support virtual memory. In other words, data is written to a swap partition when there is not enough RAM to store the data your system is processing.

In years past, the recommended amount of swap space increased linearly with the amount of RAM in the system. But because the amount of memory in modern systems has increased into the hundreds of gigabytes, it is now recognized that the amount of swap space that a system needs is a function of the memory workload running on that system. However, given that swap space is usually designated at install time, and that it can be difficult to determine beforehand the memory workload of a system, we recommend determining system swap using the following table.

Table 16.2. Recommended System Swap Space

Amount of RAM in the System	Recommended Amount of Swap Space
4GB of RAM or less	a minimum of 2GB of swap space
4GB to 16GB of RAM	a minimum of 4GB of swap space
16GB to 64GB of RAM	a minimum of 8GB of swap space
64GB to 256GB of RAM	a minimum of 16GB of swap space
256GB to 512GB of RAM	a minimum of 32GB of swap space

Note that you can obtain better performance by distributing swap space over multiple storage devices, particularly on systems with fast drives, controllers, and interfaces.

A PReP boot partition on the first partition of the hard drive — the PReP boot partition contains the YABOOT boot loader (which allows other POWER systems to boot Red Hat Enterprise Linux). Unless you plan to boot from a network source, you must have a PReP boot partition to boot Red Hat Enterprise Linux.
For IBM System p users: The PReP boot partition should be between 4-8 MB, not to exceed 10 MB.
A /boot/ partition (250 MB) — the partition mounted on /boot/ contains the operating system kernel (which allows your system to boot Red Hat Enterprise Linux), along with files used during the bootstrap process. Due to the limitations of most PC firmware, creating a small partition to hold these is a good idea. For most users, a 250 MB boot partition is sufficient.
Warning
If you have a RAID card, be aware that Red Hat Enterprise Linux 6 does not support setting up hardware RAID on an IPR card. If you already have the RAID array setup, Open Firmware does not support booting from the RAID card. In cases such as these, the /boot/ partition must be created on a partition outside of the RAID array, such as on a separate hard drive.
A root partition (3.0 GB - 5.0 GB)
This is where "/" (the root directory) is located. In this setup, all files (except those stored in /boot) are on the root partition.
A 3.0 GB partition allows you to install a minimal installation, while a 5.0 GB root partition lets you perform a full installation, choosing all package groups.
Root and /root
The / (or root) partition is the top of the directory structure. The /root directory/root (sometimes pronounced "slash-root") directory is the home directory of the user account for system administration.

Warning

The PackageKit update software downloads updated packages to /var/cache/yum/ by default. If you partition the system manually, and create a separate /var/ partition, be sure to create the partition large enough (3.0 GB or more) to download package updates.