RE: One or two partitions?
I'm a firm believer in multiple partitions, since the early days of the Mac.
For example, this g4 on which I'm typing has 3 internal drives. My primary drive has 4 discrete partitions: boot, main files (purposefully kept separate from the OS X partition), an OS 9 partition (seldom used), and a "scratch" partition (for files that I want to keep but don't deem important enough to back up).
The secondary drive consists of 3 partitions: backup of boot partition on primary drive, backup of main file partition on primary drive, and a spare.
I also have a third hard drive in the g4 with OS 10.4.11 on it (for experimentation).
Thus, I have at least FOUR bootable partitions on this g4. I can start up with OS 10.3.9, 10.4.11, and even 9.2.2 if I need it (and not that long ago, I actually _did_ need it).
In my opinion, it is ALWAYS important to have at least one additional, immediately-bootable drive. Even if you have only one internal drive (laptops come to mind), you can create a _small_ additional partition on it, and copy over a basic OS X System to it, and create an "emergency account". Even if you have software corruption in your primary OS X partition, you can probably still get going again, save a hardware failure of the drive itself.
The original poster said he had a lot of music, pictures, and movies. These are drive-space-eaters. Before too long, the drive might become so full that there wasn't enough residual free space left for the OS to operate smoothly.
An alternative course might be to create a second partition. Thus, there will be the primary boot partition on which the OS and important personal files and apps reside, and a second partition to which he can move "non-current" stuff.
Thus, the boot partition is kept "lean and mean", with the secondary partition containing the "fat".
Then, get an external backup drive, partition it, too, and use something like SuperDuper to clone BOTH partitions. Now the original poster will have both a bootable backup AND completely current copies of ALL his data, both new and old.
Once set up this way, even if something goes wrong with your main drive, you can get up and running on the secondary drive, and use what utilities you have to "attack" the problem. If push comes to shove, having a the second drive makes it easy to "wipe and dupe", restoring your primary drive from your backup.
I've even done a wipe and dupe from one partition to another. No problems.
- John
