Ok, now to the fun part, where the step-by-step guide on how to create a custom set of partitions for installing Ubuntu 12.10 starts. On a default installation of Ubuntu 12.10, the installer creates just two partitions – the partition for the root file system directory, and the Swap partition. If LVM is enabled, an extra partition mounted at /boot is created. For this manual guide, four partitions will be created – one each for /boot, /, /home, and Swap.

1. New Partition Table: To create partitions manually, you will be using the Advanced Partitioning Tool, which means that you will need to select the Something else option in the disk partitioning methods step. The screen shots used in this part were taken from a virtual environment, with about 110 GB of disk space. Because it is a brand new system, the hard drive does not have a partition table. If you encounter this situation, the thing to do is select the disk and click New Partition Table.
Install Table

Click Continue.
Partition Table

2. Use Free Space: After the partition table has been created, you now have free space that you can use to create partitions from. Select the free space and click the “+” button.
Free Space

3. Partition Creation Window: This is the partition creation window. There are no exotic options here. If there are no existing partitions on the disk, the installer will always create the first partition as a primary partition, and subsequent ones as logical partitions. If these terms are foreign to you, please take a few minutes to read guide to disks and disk partitions in Linux.
Partition Editor

4. Create Boot Partition: Here’s the same window with the values for the boot partition specified. On a default installation of Ubuntu 12.10 with LVM configured, about 255 MB of disk space is allocated to /boot, with roughly 34 MB used initially. For this tutorial, I allocated 500 MB to /boot. Any value between the default and that used here is fine. If you are really tight on disk space, you can go as low as 50 MB. For file system, I used Ext4, but on a default installation with LVM configured, the default file system is Ext2. That tells you that either one will work. For Mount point, select /boot from the dropdown menu. Click OK.
Boot Partition

Back to the main Advanced Partitioning Tool window, you will see the newly created /boot partition and the remaining free space. Select the free space, then click on the “+” button to add the next partition. This step has to be repeated for the other partitions too.
Free Space

5. Create Root Partition: For the root partition, I allocated 20 GB to it. Note that a new installation of Ubuntu 12.10 uses just 2.4 GB of disk space, so you can assign far less than 20 GB if you cannot afford that much of a disk space. The default file system is Ext4, and I stuck with that. The mount point should be /. OK.
Root Partition

6. Create Home Partition: For the /home partition, Ext4 is also the default file system. The mount point is /home, and I gave it 50 GB of disk space. OK.
Home Partition

7. Create Swap Partition: The last partition is for Swap, disk space that the system may use as memory. It has been suggested that on a 32-bit system, 2 GB is all you need for Swap, and 4 GB or more for a 64-bit machine. Be sure to select “swap area” from the Use as dropdown menu. OK.
Swap Partition

8. List of Partitions: When all the partitions have been created, they should all be listed in the main window. Notice that I left some free space unallocated, just in case I want to create a shared NTFS partition between Windows 7 or 8 and Ubuntu, when dual-booting.
All Partitions

That ends this tutorial. If you want to install Ubuntu 12.10, you may download an installation image from here.