Using external hard drive with both iMac and PC

Question

I own an old Dell PC and an iBook, and will soon replace the Dell with an iMac.
I recently bought a 250GB Western Digital external hard drive to back up my data. I would like to use this hard drive to back up all of the files that are on the PC (which I will soon be getting rid of) and also use it for backing up the files on the iBook and, when it arrives, the iMac. In other words, neatly back up all my info onto the back-up drive.
My question is this: can I do this? If not, what is the best way to consolidate all of the data from all of these computers into one place? Will the fact that some data comes from a PC and some from a Mac be a problem? Can you move back-up drives fromone computer to another? The photos on my PC are saved in Picasa, whereas the photos on the iBook are in iTunes. My iPod music files are all on the PC in iTunes.
Any advice about backing all this stuff up in a user friendly way would be greatly appreciated.
By the way, I have heard that there are ways to reformat external drives, to partition them, and to "raid" them. Can someone explain what this all means?
Thanks.
iBook G4    

Answer 1

Hello,
Your best option would be to store the files from your PC on the drive with the drive in the FAT32 format. Then, copy the files to your Mac's Internal hard drive.
Now, once the files are stored safely on your Mac's internal hard drive, you can safely reformat the external drive as a Mac OS X Extended (Journaled) drive. That will be the best format to use for long-term purposes with your Mac.
Many OS X file types (such as many PKG files) cannot be stored / written to a FAT32 volume. So, a FAT32 drive would not be suitable for backing-up an entire OS X hard drive (or even many of the system updates that you might download).
So, that's how I'd do it. Use the drive as a FAT32 just long enough to get the files moved to your Mac.
Once the drive is re-formatted in the Native Mac format, then you could copy the files back to it, and any other Mac files that you wanted to back-up to it for safe-keeping.
Personally, I would re-partition it in at least two pieces on the Mac. One to hold data / personal files for safe-keeping, and a second bootable partition for a full system / OS X backup.
You can read a bit more about this in some of my previous discussions here:
http://discussions.apple.com/thread.jspa?messageID=2536703&#2536703
http://discussions.apple.com/thread.jspa?messageID=2597825&#2597825
http://discussions.apple.com/thread.jspa?messageID=2632566&#2632566
Read through each of those three discussions and you'll see how they all come together and provide you with a good solution for backing-up your hard drive.
I hope you don't mind my linking you to those other discussions, but it just seemed more practical than re-typing what I had already said all over again
Also, if you are getting one of the new Intel iMac systems, and you want to be able to create a bootable backup as described in those posts, be sure to format your external hard drive using the new GUID format. That will provide you with the best solution.
I hope this helps.
Let us know if you have other questions.
P.S., if you'd like, go ahead and click the "Helpful" or "Solved" buttons on any of the posts / replies above if you feel they were helpful or adequately answered your question.