Creating An Extended Partition
Creating an Extended Partition is done the same way as creating a Primary partition. Remember the "Primary" type in the menu of the screenshot that I mentioned earlier? That is the menu in which we select the creation of an Extended Partition:
Notice the menu selection in the "Create As" box. Where we left Primary selected for creation of a Primary partition, this time we select Extended. When Extended is selected, all the file types in the menu below will be greyed out. There is no file type associated with an Extended partition. An Extended Partition is basically a container for any number of Logical partitions, which can be of any file system format.
Above is the created Extended Partition. You would normally cover the entire remaining free space with this partition unless you intend to install another Operating System which requires free space to be installed into. The extended partition is represented by a box in the graphics portion surrounding the remaining free space. The Extended partition can be resized to create room for expansion of the existing Primary partition or the creation of (an) additional Primary partition(s).
You will notice a third partition type option in the "Create As" drop-down menu. This option is to create a Logical partition inside of the Extended partition we are about to create.
When you click on a free space, which type of partition that may be created depends on the location of the free space you are selecting. If it is outside of an extended partition, you will only be able to create a Primary or an Extended partition. If the free space resides within an Extended partition, you will only be allowed to create a Logical partition. Creating a Logical partition is otherwise exactly the same as creating a Primary partition.
Below, I have erased all the partitions that I created earlier in "Primary Partition Rules and Conventions" except for the Primary NTFS partition (which would contain the Windows Operating System) and replaced them with an extended partition covering the rest of the free space. I then created a number of logical partitions inside of it to demonstrate how an extended partition works:
Notice that I have recreated the original Linux partitions and created 5 more partitions, called logical partitions, of various filesystems within the extended partition to demonstrate how an extended partition works. Note also the order of the list of partitions below the graphics. Any partition that preceeds the Extended partition is a Primary partition. Those that follow it in the list are Logical partitions. I can create any number of Logical partitions, of any file type and any size, within this Extended partition.
Note that you can apply any operation to an extended partition except formatting it as a filesystem. You must create Logical partitions within it, and those may be formatted.
Note also that an Extended partition cannot be deleted until all the Logical partitions existing in it are deleted first.