I have a 500gb Seagate HDD in my 2010 slim PS3 (but has content carried over from a 2006 launch PS3, so about basically the whole drive was near max capacity with years of content/media/game saves), and it started acting up yesterday, or should I say the PS3 firmware was.
I was low on disc space, yet the PS3 didn't give the "cannot install, not enough space" message. Instead, it started installing what it couldn't. The install process would halt and the only way to exit out was to yank the power cord (power button didn't work and can't back out on-screen either).
It started to install incomplete files (game data) and would come up as "Corrupted data". When trying to delete that data, it would grind to a halt - I come back about an hour later and it's still on the "deleting..." screen. Yet again, only option was to yank power cord.
Then when turning on the PS3 again, it says the file system is corrupt and must be restored. Alright, so it gets around 40%. Error, restore failed and you must format the PS3 HDD.
I didn't do it at first. I tried 3 more times. Same result. So I then "formatted".
However the "format" went very fast, and I don't think it really wiped everything. I think data is still there and has not been overwritten yet, and may be able to be restored/undeleted somehow.
After the "format", only the profiles/passwords remained (those are stored on the PS3 flash memory and not the HDD).
All of my photos, gone (thousands of custom Home photos I was meaning to upload online, wallpapers, and even family photos that I don't have backups of). All of my videos (lots of recorded in-game footage, and now taken down trailers and programs and clips from Japan Store etc), gone. All of my downloaded games (hundreds when combining PSOne Classics and PSN) gone. All of my music, gone (lots of great WipeoutHD custom soundtracks and such). But most importantly, all of my game saves, gone (tons and tons of work in games, some 100+ hours, down the drain, and some with Trophies incomplete where I would have to start from scratch). And no I foolishly didn't take advantage of the recent Online Saves/cloud storage with PS+.
I don't care about undeleting/restoring the downloaded games. What I really care about are the photos, videos and most importantly game save files.