There is a way to make the HDD not format, but regardless, it's very stressful, and it's very tedious. Honestly, I wouldn't recommend doing it on a slim PS3, but a FAT might possibly work. But like I said...it's a pain in the ass. The HDD gets reformatted every time you take it out, or put one, or the same back in. I thought by swapping HDD'S at one time, I could change the 1.11 patches in MW2. All that needed to be done was just copy the modded patch_mp.ff over. :dumb:
I wouldn't recommend anyone do this unless you know what you're doing. The HDD is a very sensitive device...so don't throw it...at the wall...or anything.
I totally did that once. My PS3 was still under a one year warranty, and it just said it was corrupted. Sony had to fix it. :lol: