How to recover files from old CD/DVD-R?
January 4, 2016 10:21 AM Subscribe
I have a decent number of 10+ year old CD-Rs and DVD-Rs, and a few of them have started to go south. I'd like to pull off as much of the data as possible, even if it means an audio glitch or a corrupted bit of an image here and there. (Where at the moment, the OS X Finder just gives up and I don't get any part of the damaged file at all.) Is there an app or technique you would suggest for this purpose?
I realize similar questions have been asked before, but as the last one was in 2008, I'm hoping there might have been some improvements in recovery tech in the last seven years.
I have tried multiple different optical drives, including some old ones. Surprisingly, my most recent Samsung BD-R drive has been the best at reading everything. The issue isn't really scratches or anything I can polish out, but seems to be a failure of either the dye or reflective layer on the recordable media. (Maxell is the biggest culprit on the latter, with the reflective layer delaminating and just peeling away.)
Data Rescue, my go-to for recovering data from hard drives, has specifically told me that it won't work on optical drives, so that's out. It seems that most of the other popular Mac data utilities have the same restriction.
This data isn't important enough to spend $$$ at some data recovery company, but if I can increase my chances of recovery before trashing these old discs, that would be keen.
I realize similar questions have been asked before, but as the last one was in 2008, I'm hoping there might have been some improvements in recovery tech in the last seven years.
I have tried multiple different optical drives, including some old ones. Surprisingly, my most recent Samsung BD-R drive has been the best at reading everything. The issue isn't really scratches or anything I can polish out, but seems to be a failure of either the dye or reflective layer on the recordable media. (Maxell is the biggest culprit on the latter, with the reflective layer delaminating and just peeling away.)
Data Rescue, my go-to for recovering data from hard drives, has specifically told me that it won't work on optical drives, so that's out. It seems that most of the other popular Mac data utilities have the same restriction.
This data isn't important enough to spend $$$ at some data recovery company, but if I can increase my chances of recovery before trashing these old discs, that would be keen.
A live linux distrubution (e.g., ubuntu desktop on a usb key) with both cdparanoia and ddrescue may be worth a try. I've had great luck reading audio discs that couldn't be accessed any other way.
posted by eotvos at 10:30 AM on January 4, 2016
posted by eotvos at 10:30 AM on January 4, 2016
Best answer: If memory serves, PhotoRec was the go-to for this kind of thing. (It is not photo-specific, despite the name.)
posted by mrg at 10:32 AM on January 4, 2016
posted by mrg at 10:32 AM on January 4, 2016
I've used IsoBuster for extracting data from bad optical disks.
posted by zsazsa at 11:54 AM on January 4, 2016
posted by zsazsa at 11:54 AM on January 4, 2016
Response by poster: Thanks for the recommendations, everyone. I'm going to try PhotoRec first, since that runs on Mac OS X natively and will require the least amount of alternate-OS jiggery-pokery, but I'm glad to have multiple options!
posted by mboszko at 3:05 PM on January 4, 2016
posted by mboszko at 3:05 PM on January 4, 2016
Photorec is good for pulling files off damaged filesystems, but the important thing for you is to read as much data off the disks to start.
If the disk is physically damaged, you need to extract all the bits off the disk you can, and then feed the resulting file (a disk image) into PhotoRec. gddrescue is my go-to tool for pulling data off a failing hard drive (it skips over failed sectors, which tend to come in groups, to find and copy undamaged areas first). gddrescue takes a disk and gives you a disk image, which you can either attempt to mount as a filesystem, or if the filesystem is damaged, you can ask PhotoRec to try to extract files from the disk image brute-force.
I would use cdparanoia to rip the disks (instead of ddrescue since gddrescue is, to my knowledge, written for hard drives). If at all possible, you really really want a perfect rip of the disk and I think cdparanoia is designed to do that (though I don't have any experience with it myself). If no matter what you end up with a partially-bad rip, point PhotoRec at the disk image to recover any files that are physically there, but it's a last resort imho- PhotoRec is magic, but you want as many good bits off the disk to feed it.
posted by BungaDunga at 6:44 PM on January 4, 2016 [1 favorite]
If the disk is physically damaged, you need to extract all the bits off the disk you can, and then feed the resulting file (a disk image) into PhotoRec. gddrescue is my go-to tool for pulling data off a failing hard drive (it skips over failed sectors, which tend to come in groups, to find and copy undamaged areas first). gddrescue takes a disk and gives you a disk image, which you can either attempt to mount as a filesystem, or if the filesystem is damaged, you can ask PhotoRec to try to extract files from the disk image brute-force.
I would use cdparanoia to rip the disks (instead of ddrescue since gddrescue is, to my knowledge, written for hard drives). If at all possible, you really really want a perfect rip of the disk and I think cdparanoia is designed to do that (though I don't have any experience with it myself). If no matter what you end up with a partially-bad rip, point PhotoRec at the disk image to recover any files that are physically there, but it's a last resort imho- PhotoRec is magic, but you want as many good bits off the disk to feed it.
posted by BungaDunga at 6:44 PM on January 4, 2016 [1 favorite]
Response by poster: BungaDunga, I'm not sure I understand how ripping with cdparanoia would help — from the docs on its website, it seems like it's geared only toward ripping audio CDs? Maybe I misunderstand how it works.
posted by mboszko at 9:20 PM on January 4, 2016
posted by mboszko at 9:20 PM on January 4, 2016
You are right; it looks like it is for audio CDs only.
posted by BungaDunga at 9:32 PM on January 4, 2016
posted by BungaDunga at 9:32 PM on January 4, 2016
oh, i thought the CDs were, well, CDs. sorry.
posted by andrewcooke at 2:57 AM on January 5, 2016
posted by andrewcooke at 2:57 AM on January 5, 2016
Response by poster: All sorts of data on these. Some audio CDs. Some VCDs. Some full of MP3s, pictures or other files. They're just on CD-R because DVD-R didn't exist yet (or was more expensive per MB, once it did). Some of them are close to 20 years old. Of course I've got a ton of DVD-Rs too, but I'm going through them roughly chronologically, and not sure how those have held up yet.
posted by mboszko at 7:47 AM on January 5, 2016
posted by mboszko at 7:47 AM on January 5, 2016
This thread is closed to new comments.
posted by andrewcooke at 10:28 AM on January 4, 2016