2.12. Partitioning Your System
At this point, you must tell the installation program where to install Red Hat Enterprise Linux. This is done by defining mount points for one or more disk partitions in which Red Hat Enterprise Linux will be installed.
The partitioning tool used by the installation program is Disk Druid. With the exception of certain esoteric situations, Disk Druid can handle the partitioning requirements for a typical installation.
2.12.1. Graphical Display of DASD Device(s)
Disk Druid offers a graphical representation of your DASD device(s).
Using your mouse, click once to highlight a particular field in the graphical display. Double-click to edit an existing partition and assign a mount point.
Above the display, you can review the Drive name (such as /dev/dasda), the Geom (which shows the hard disk's geometry and consists of three numbers representing the number of cylinders, heads, and sectors as reported by the hard disk), and the Model of the hard drive as detected by the installation program.
2.12.2. Disk Druid's Buttons
These buttons control Disk Druid's actions. They are used to change the attributes of a partition (for example the file system type and mount point) and also to create RAID devices. Buttons on this screen are also used to accept the changes you have made, or to exit Disk Druid. For further explanation, take a look at each button in order:
Edit: Used to modify attributes of the partition currently selected in the Partitions section. Selecting Edit opens a dialog box. Some or all of the fields can be edited, depending on whether the partition information has already been written to disk.
Make RAID: Make RAID can be used if you want to provide redundancy to any or all disk partitions. It should only be used if you have experience using RAID. To read more about RAID, refer to the RAID (Redundant Array of Independent Disks) chapter in the Red Hat Enterprise Linux System Administration Guide.
To make a RAID device, you must first create (or reuse existing) software RAID partitions. Once you have created two or more software RAID partitions, select Make RAID to join the software RAID partitions into a RAID device.
2.12.3. Partition Fields
Above the partition hierarchy are labels which present information about the partitions you are creating. The labels are defined as follows:
Device: This field displays the partition's device name.
Mount Point/RAID/Volume: A mount point is the location within the directory hierarchy at which a volume exists; the volume is "mounted" at this location. This field indicates where the partition is mounted. If a partition exists, but is not set, then you need to define its mount point. Double-click on the partition or click the Edit button.
Type: This field shows the partition's type (for example, ext2 or ext3).
Format: This field shows if the partition being created will be formatted.
Size (MB): This field shows the partition's size (in MB).
Start: This field shows the cylinder on your hard drive where the partition begins.
End: This field shows the cylinder on your hard drive where the partition ends.
Hide RAID device/LVM Volume Group members: Select this option if you do not want to view any RAID device or LVM Volume Group members that have been created.
2.12.4. 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. The size of your swap partition should be equal to twice your computer's RAM, or 256 MB, whichever amount is larger, but no more than 2048 MB (or 2 GB).
For example, if you have 1 GB of RAM or less, your swap partition should be at least equal to the amount of RAM on your system, up to two times the RAM. For more than 1 GB of RAM, 2 GB of swap is recommended. Creating a large swap space partition can be especially helpful if you plan to upgrade your RAM at a later time.
Tip If your partitioning scheme requires a swap partition that is larger than 2 GB, you should create an additional swap partition. For example, if you have 4 GB of RAM, you may want to create two 2 GB swap partitions.
A /boot/ partition (100 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 BIOSes, creating a small partition to hold these files is a good idea. For most users, a 100 MB boot partition is sufficient.
A root partition (1.2 - 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 1.2 GB root partition permits the equivalent of a basic installation (with very little free space), while a 5.0 GB root partition lets you install all package groups.
A /var/ partition (3.0 GB or larger) — the /var/ partition is where variable data files are written. This includes spool directories and files, administrative and logging data, and transient and temporary files. Updates that are applied to Red Hat Enterprise Linux are written to the /var/ partition.
