Thread: Linux multi-booting template

People often ask why there are so many Linux distributions. No one seems to ask why there are so many items in a buffet spread or so much variety in a botanical garden.

The large number of distributions sure makes it difficult to pick the right one for a particular task; but having picked the right distribution. you have it better adapted for the task at hand. You may not be able to sample all the items on a buffet. but you certainly can multi-boot your machine with a bunch of lively Linux distributions and zero in on your favourite set or-even better-keep all of them.

Look at it another way. You share a couple of Linux (of course!) PCs at home with family members with diverse requirements: your grandmother wants simplicity, the cousin wants multimedia, the kids want games and education tools, and you want to tryout the latest distributions. Now you can meet all these requirements and pamper yourself in the bargain.

Let us get straight into looking at a partition and multi-boot scheme that you can use as-is or tailor to your requirements. I'm assuming that you understand the basics of partitioning, boot loaders, and have installed Linux distributions in the past. Even if you haven't, I am sure you can get a leg-up from the neighbourhood know-all.

Template

Our partition and multi-boot scheme has a two-level boot menu. It has a master boot menu listing all the installed distributions available for booting. Once you select the distro to boot from, you are taken to the dedicated GRUB menu of the specific distro you are booting.

Fbr instance, when I select 'openSUSE 11' on the master boot menu, I am taken to the SUSE boot menu that lists the various options to boot openSUSE such as:
a 'normal boot' or a 'fail-safe session'. We will revisit boot menus l<!ter in this article. For the moment let us get down to partitioning our disk. We are assuming a blank hard disk to keep things uncomplicated. You can start the partitioning session from a live CD such as Knoppix.

Start with a primary partition (sdal) of about 100 MB for Iboot followed by a primary partition (sda2) for swap of a suitable size. Make sure the swap is larger than your RAM because this is the space used by the suspend-to¬disk feature on some distros.



Of the remaining two primary partitions possible, make one an extended partition. This extended partition (sda3) will house the following logical partitions:

• A partition (sda5) to mount as a common Itmp directory for all distributions. About 2 GB for I tmp should do for most people, but again this is a suggestion and not a recommendation.

• Slots (sda6, sda7, and so on) for the various distributions. About 10-12 GB per distribution should be adequate for most distributions and you could even do with less.

The fourth primary partition (sda4) can be mounted as the common Ihome directory for all distributions. A common Ihome across distributions can lead to some irritations related to the desktop and we will explore a workaround later when discussing usage scenarios. If you have a capacious hard disk (and who doesn't these days), you can have more than one partition available for mounting as Ihome and specify which one to mount automatically for a particular distribution during install time.

If you have more than one partition for Ihome, make sure you create the additional ones as logical partitions inside the extended partition sda3. Choosing a common swap and Itmp partition across distributions helps you utilise your hard disk real estate that much better. You have a choice of file system types to use for each partition, but remember that GRUB is finicky and prefers ext3.

Depending on how much space you need for swap, Itmp and Ihome, you can easily arrive at how many distributions you can pack into a single hard disk. As a variation you can also pack all distributions on one hard disk and keep your data on another.
Table 1 shows how the partitions might look like for a single disk of 120 GB with three distributions sharing a common home partition.