A. Keep your Recovery partition at 8GB; keep your data / Time Machine backup on a separate partition
Let’s you keep the bare basics, if that’s all you need. You just won’t be able to install any OS updates, but it will make installing a fresh OS easier on your Recovery partition easier.
B. Make your Recovery partition larger; keep your data / Time Machine backup on a separate partition
Still run into the possibility of running out of space on your Recovery partition depending on size of OS Updates, number of applications you still, and the size of the partition. At the same time, it also still makes installing a fresh OS easier.
C. Share your Recovery partition with your data / Time Machine backup
Not as big of a worry about running out of space for the Recovery partition as it’ll be stored on the largest partition available on your external hard drive. OS X must be installed on partition before Time Machine is used with it. Installing a fresh OS will be a little more troublesome as you cannot install OS X on a Time Machine drive/partition (which is why we will install OS X on it beforehand).
D. Doesn’t matter. I’m using a Flash Drive and/or SD Card.
If you’re using a Flash Drive or SD Card, it’s very likely you’re not worried about a data / Time Machine partition.
A. 1 Partition
If you’re using a Flash Drive or SD Card that is 8GB in size, you’ll only have enough room for 1 Partition.
B. 2 Partitions
If you’re using a Flash Drive or SD Card that is 16GB in size or larger, or you’re using an external hard drive in which you’ll be sharing your Recovery partition with your Time Machine / other data, select 2 Partitions.
C. 3 Partitions
If you’re using an external hard drive and want to keep your Recovery partition and Time Machine / other data separate, select 3 Partitions.
A. Enter the Name of the volume(s)
This is the name of the partition as it will show in the Finder. Try to name each partition something easy to recognize.
For example, the first partition of the storage device is where I will be storing my Mac OS X Install DVD, so I would call it Mac OS X Install HD, Mac OS X Install USB, or Mac OS X Install SD, depending on the device I install it on. The name is completely up to you.
B. Select Mac OS Extended (Journaled) as the volume(s) Format.
No matter what, each partition must be formatted Mac OS Extended (Journaled) as this is the only recognizable format Mac OS X will understand when using it as a bootable device or for Time Machine.
C. Enter the Size of the volume(s)
If you are using a 1 Partition setup, use the maximum size available to you.
Otherwise, it’s important that this first partition be a minimum of 6.74GB, the size of the Mac OS X Snow Leopard Install DVD. I recommend a size of 8GB so that you can future-proof yourself for future releases of Mac OS X.
On a 2 Partition setup, use the remaining available space on your storage device.
On a 3 Partition setup, the second partition must be a minimum of 8GB. Again, if you plan on installing system updates and additional software, it’s recommended you make this partition larger. The third partition will use whatever space is remaining.