12.19. Partitioning Your System

New: Used to request a new partition. When selected, a dialog box appears containing fields (such as the mount point and size fields) that must be filled in.

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.

You can also edit free space as represented in the graphical display to create a new partition within that space. Either highlight the free space and then select the Edit button, or double-click on the free space to edit it.

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.

Delete: Used to remove the partition currently highlighted in the Current Disk Partitions section. You will be asked to confirm the deletion of any partition.

Reset: Used to restore Disk Druid to its original state. All changes made will be lost if you Reset the partitions.

RAID: Used 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, see the Red Hat Enterprise Linux Deployment Guide.

To make a RAID device, you must first create software RAID partitions. Once you have created two or more software RAID partitions, select RAID to join the software RAID partitions into a RAID device.

LVM: Allows you to create an LVM logical volume. The role of LVM (Logical Volume Manager) is to present a simple logical view of underlying physical storage space, such as a hard drive(s). LVM manages individual physical disks — or to be more precise, the individual partitions present on them. It should only be used if you have experience using LVM. To read more about LVM, see the Red Hat Enterprise Linux Deployment Guide. Note, LVM is only available in the graphical installation program.

To create an LVM logical volume, you must first create partitions of type physical volume (LVM). Once you have created one or more physical volume (LVM) partitions, select LVM to create an LVM logical volume.

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 file system type (for example, ext2, ext3, or vfat).

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.

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.

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 PPC PReP boot partition on the first partition of the hard drive — the PPC 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 floppy or network source, you must have a PPC PReP boot partition to boot Red Hat Enterprise Linux.

For IBM System i and IBM System p users: The PPC PReP boot partition should be between 4-8 MB, not to exceed 10 MB.

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 firmware, creating a small partition to hold these is a good idea. For most users, a 100 MB boot partition is sufficient.

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.

Mount Point: Enter the partition's mount point. For example, if this partition should be the root partition, enter /; enter /boot for the /boot partition, and so on. You can also use the pull-down menu to choose the correct mount point for your partition. For a swap partition the mount point should not be set - setting the filesystem type to swap is sufficient.

File System Type: Using the pull-down menu, select the appropriate file system type for this partition. For more information on file system types, refer to Section 12.19.5.1, “File System Types”.

Allowable Drives: This field contains a list of the hard disks installed on your system. If a hard disk's box is highlighted, then a desired partition can be created on that hard disk. If the box is not checked, then the partition will never be created on that hard disk. By using different checkbox settings, you can have Disk Druid place partitions where you need them, or let Disk Druid decide where partitions should go.

Size (MB): Enter the size (in megabytes) of the partition. Note, this field starts with 100 MB; unless changed, only a 100 MB partition will be created.

Additional Size Options: Choose whether to keep this partition at a fixed size, to allow it to "grow" (fill up the available hard drive space) to a certain point, or to allow it to grow to fill any remaining hard drive space available.

If you choose Fill all space up to (MB), you must give size constraints in the field to the right of this option. This allows you to keep a certain amount of space free on your hard drive for future use.

Force to be a primary partition: Select whether the partition you are creating should be one of the first four partitions on the hard drive. If unselected, the partition is created as a logical partition. Refer to Section 26.1.3, “Partitions within Partitions — An Overview of Extended Partitions”, for more information.

Encrypt: Choose whether to encrypt the partition so that the data stored on it cannot be accessed without a passphrase, even if the storage device is connected to another system. Refer to Chapter 29, Disk Encryption Guide for information on encryption of storage devices. If you select this option, the installer prompts you to provide a passphrase before it writes the partition to the disk.

OK: Select OK once you are satisfied with the settings and wish to create the partition.

Cancel: Select Cancel if you do not want to create the partition.