I should have maybe asked some other questions first before stating my plan to partition since I know so little about the mac system.
The reason I like to keep my data files separate is if I ever have to restore my system I don't need to worry about losing my personal files. I really don't like the iPad file system since it is very hard - sometimes impossible -to share files between apps. Is the mac file system similar or can I save say all my videos on one drive (external) and access them from any program?
So why is it unadvisable to partition the drive, using one for the system files and one for data files? Is this a general consensus for mac users or mainly a personal preference?
It's clearly only a personal preference, but one that has arisen over many years. I fought the system for many years, trying to keep a small "C:" drive and kept running into problems with apps not respecting that and insisting that they must install on "C:" etc... A precursor to my return to the Mac platform was letting go of this, as well as giving in to iTunes' organization of my music, etc...
Mac OS X is a Unix based system. Unlike Windows, there is no concept of drive letters, and everything looks like a file or folder. Including devices and many other things that are not so on Windows. Generally a separate partition will mount under the "/Volumes" folder, so a data partition might be accessed as "/Volumes/Data".
With backup and restore tools like the built in Time Machine and Carbon Copy Cloner (CCC), it's just as easy to create separate backups of your system and /Users/rkayd as it is to backup /Volumes/Data. They are both essentially folders. The partitioning doesn't really buy you anything.
Another advantage of Mac OS X over Windows is that you can, using CCC or SuperDuper, create a perfect
bootable clone of your system on a removable drive. Then, you don't even have to restore your system, just boot from the clone when you have an issue.
Unlike iOS, you have full access to the file system just as you would on Windows or another Unix. You can store data files anywhere you want to, including an external drive or NAS.
Macs also use EFI and GPT instead of BIOS and MBR for the boot process. This is (partially) why Boot Camp Assistant doesn't work unless your internal drive is a "single" partition. There is actually a hidden FAT system partition on top of the OS partition and Lion further adds a system restore partition to the mix. This leaves only a single partition for Windows to stay within the 4 partition MBR limit (a hybrid MBR is still required to boot most versions of Windows.)
So, again, if you were leaving Windows behind altogether or if you were familiar with Mac OS or Unix to begin with. You could go with a partitioned system, otherwise I would recommend leaving it to the default at least until you have used it like that for a while....
I've helped enough folks around here who have created work and/or problems for themselves in multi-partition systems that I don't need that kind of aggravation myself.
B