Recipe 12.5. Preparing a System for Multibooting Linux

12.5.1 Problem

You plan to multiboot several different Linux distributions, and you want to prepare your system. You want a standalone /boot partition and shared /home and /swap partitions.

12.5.2 Solution

Most Linux distributions let you customize the partitioning during installation. Create new partitions only as you need them during each installation, and leave free space for additional installations.

Let's walk through a clean Fedora installation on a 20-GB IDE drive, using this partitioning scheme:

/dev/hda1	Primary	100 MB	/boot
/dev/hda2	Primary	2,500 MB	/
/dev/hda3	Primary	3,000 MB	/home
/dev/hda4	Extended
/dev/hda5		256 MB	/swap
Free space		14,144 MB

Here are the steps:

1. Boot up the first installation CD. Select your keyboard, mouse, and display. When you get to the Disk Partitioning Setup window, select "Manually partition with Disk Druid." A nice graphical display shows your hard drive.

2. Delete any existing partitions. Highlight them one at a time, then click the "delete" button.

3. Next, highlight "Free Space," and click "New." The mountpoint is /boot. Select Ext2 for the filesystem, and enter the partition size. One hundred megabytes is the minimum Fedora will accept for /boot. Click OK. That is now /dev/hda1.

4. Highlight "Free Space" again and click "New." The mountpoint is /. Select Ext3, 2500 MB. Click OK. That's /dev/hda2.

5. Highlight "Free Space" again and click "New." The mountpoint is /home. Select Ext3, 3000 MB. Click OK. That's /dev/hda3.

6. Highlight "Free Space" again and click "New." Scroll down "filesystem options" until you find "swap." There is no mountpoint; make it 256 MB. Click OK. This is /dev/hda5.

7. At this point you may go back and make changes, because the new partition table has not yet been written to disk. When you're finished, write the changes to disk by clicking OK in the main Disk Druid menu.

Now you can continue with the installation. Make sure that you install GRUB, not LILO. When you install additional Linuxes, they will share /home and /swap. You can install any number of Linuxes, until your disk is full or you have used all available partitions.

12.5.3 Discussion

Most modern Linux distributions install GRUB by default. Make sure you don't install LILO.

QTParted is an excellent graphical utility for creating, deleting, moving, and resizing disk partitions. QTParted is included on Knoppix, so you can set up your partitioning before installing a new Linux, if you prefer. You can also make changes after installation, even to partitions with data on them. Of course, you must have good backups first. QTParted does a good job, but messing with partitions can backfire.

Putting /swap on its own partition improves performance, and it can be shared on a multiboot system. Giving /home its own partition lets you share it between the different Linux systems you're running, and it allows you to do all sorts of system installations and removals without forcing you to restore your data from backup every time.

Linux partitioning is limited to 63 partitions per IDE drive: 3 usable primary partitions, with the 4th containing up to 60 logical partitions in a single extended partition.

SCSI drives are limited to 15 partitions per drive: 3 usable primary partitions, and 12 logical partitions in a single extended partition.

12.5.4 See Also

• fdisk(8)

• Chapter 13

• QTParted home page (http://qtparted.sourceforge.net)