Computer help -- munged up partition table!

[djmcmath]

I hate it when this happens. The bright side is that it's a fairly entertaining bit of nerd-ery.

So I've got a 60GB Maxtor that I've been using for large data storage in my secondary machine. It's where I rip my CDs to, and where the digital photography gets stored, that sort of thing. Trouble is that I didn't realize it was only 60GB when I did the last partitioning. For whatever reason, Partition Magic let me format this thing with somewhere upwards of 130GB on the drive.

Now, I didn't remember ever having bought a drive that large, but it was great to have that much space, because it meant I could keep the two OS partitions alive in the first 30GB of the drive, and still have this massive data partition on the back 100GB (much of which didn't really exist).

So I've been slowly filling this drive, bit by bit, for a while, with no problems. Last night, I reboot my machine because it's running a little sluggishly, and the large data drive isn't on the list under "My Computer". After some investigation, I end up pulling up the partition table, which is completely buggered up. It looks, for all intents and purposes, like I wrote off the end of the drive and started back over at the beginning. Now, I've got some pretty low level tools for mucking around in partition tables. I could type individual values for any bit I felt like. I just don't particularly feel like making it worse than it already is.

Anyone here have any brilliant recommendations on how to un-bugger my partition table?

Thanks in advance,

Dan

[Paul_Heery]

Try the Gnome Partition Editor. It is a LiveCD (or LiveUSB) that will boot to a graphical interface for managing partitions.

[Joeaksa]

Hmmm, how can you "write off the end of the drive?" so to speak. I have always gotten a warning that the partition or drive was close to being full or was full and it would not transfer data at that point.

Partition magic is also very good for working with drives.

Dan, I really, really, really hope that you are not using a single drive to store all of your digital stuff?

Please go to a good computer store and get at least a USB drive to plug in and make a backup of everything digital. I use my old computer that is networked to the current desktop, AND 3 USB drives for photos, movies, music and documents. I then also backup the important stuff that I need right now on the laptop as well. That way its stored on at least 3 separate sources and I am not going to lose all 3 at one time. 500 gig USB drives are going for about $110 these days at Fry's electronics and a good way to keep things saved.

[Neilk]

I've used PartitionMagic in the past and the version I used prompted us to save the Partition info to a floppy disc so you could restore the drive if it got messed up. Did you get that option? I guess that's a dumb question if you are asking us.

Oops. Ignore my info above. I just reread your post.


I used a dos prompt tool once to copy the files on a messed up drive to a second drive. I can see if I can find the name of the program when I get home. I would add a second IDE drive to the PC and try to copy all the bits from the old drive to the new one. A USB drive might not work well with backup tools, especially a DOS based one.

[Joeaksa]

Neil,

My version did not but ran on the main drive as a stand alone program. You might have had an older version.

Am overseas working now or would email you guys the program. Do not keep a copy of it on the laptop. Might try www.downloads.com and see if you can download an older version for free.

Joe

[SlowToady]

He was able to write off the end of the drive and start back at the beginning because the way the partition table was setup, it was setup for a drive 2x as large as the actual capacity. Basically, there wasn't any way the OS to know that drive was full or almost full, since it reads the partition table to determine drive space.

Not sure WTF Partition Magic let you do that...that's _really_ odd. Maybe you can submit to their Errata?

Hmmm, how can you "write off the end of the drive?" so to speak. I have always gotten a warning that the partition or drive was close to being full or was full and it would not transfer data at that point.

[SlowToady]

Dan, are you trying to save the data that you have left after writing over the disk again? If so, I have some good NTFS / FAT32 recovery software, but Data Recovery isn't the most trivial task you could take off. Read the documentation, think it through, and be careful.

I probably would just completely wipe it, and start over...

[Joeaksa]

Originally Posted by SlowToady

I probably would just completely wipe it, and start over...

If and only if you have backups made of the data on the drive. This is not for the faint of heart and you can lose a lifetime of work in a flash if not careful.

[djmcmath]

The big picture is, in fact, that PQ Magic let me make a dumb mistake. I shot myself in the foot with this one, when I realized late last night that the size of the drive was about half what I thought it was. In fact, if the partition table is wrong and says that there are bits available out past the end of where there are really bits, the OS has no way of knowing where to stop writing.

Regarding backups, I am terrible about backups. The really critical stuff -- the wedding pictures -- are backed up to DVD and copies are sent to people who care. Everything else is just a hassle (for the most part) to replace, or would consume a lot of time, or isn't really that critical anyway. I keep all of my film-based work scanned on the computer as well, and it takes about half an hour to scan a roll of film. Re-scanning 300 rolls of film is a monstrous project that I really don't feel like undertaking, but ... if the data's gone, it's gone. I have pictures of my niece and nephew from my time home at Christmas a few months ago, and if I really need them, I think I left copies on my parent's computers before I left ... So if the data's gone ... it's gone. I'd just rather that it not be gone.

I know that in a technical sense, the bits are still there. I've just lost the easy way of getting to them. I would be ecstatic if I could find a way to recover that data -- which is why I'm here getting second opinions before I start manually tweaking bits in the partition table or something.

Paul -- GParted looks like a great tool, I'll give it a shot. In fact, it looks like an open source version of PQMagic, which would make me very happy indeed.

I already have, btw, an interesting tool that allows me to basically insert arbitrary values into the partition table. I could try to take a picture of the current output of that display ... you'd probably all be shocked at the havoc that I've wreaked on this drive. I spend too much time at work maintaining computers correctly to get it right at home, I guess. Anyhow, it's pretty powerful ... I just don't know what values to put in to most likely assure recovery.

SlowToady, you've pulled my fat out of the fire before. If you have a tool you recommend, I'll trust you whole-heartedly.

Thanks again, all.

Dan

[svandamme]

the fact that PM made you format a disk at 130 when it's really an 60
makes me think that the disk was buggered to begin with

because normally , it would detect the actual disk size, and not show you 130 gig when there aren't that many... even if you would have manually set the disk to 130 in the BIOS, PM would normally detect it as 80

[djmcmath]

Stijn, that's an interesting point. What's even more weird is that I can still bring it up in PQMagic and see the "unallocated space" which used to be my drive. As far as PM is concerned, it's just not formatted anymore. I wonder if I could go poking into the partition table and just say, "Congratulations, you're formatted again! " and make everything ok. But you're probably right -- it's time for this drive to go to that Big Computer in The Sky.

I'm running a demo of a program called Get Data Back right now, as recommended privately by another Pelican. It'll probably go for A Long Time. I'll see if it will let me recover anything, or how well it works, or what, and go from there. If I can back up a bunch of the data that way, then I might start playing with the partition table. What have I got to lose?

Thanks,
Dan

[djmcmath]

Alright, after a few weeks of working on this problem, it's time for some follow up. I ended up using a tool named "Recover My Files," which worked reasonably well. Not perfect, and not really good enough, but ... well, ok, here's the break down:

JPG images, like the sort you'd take with a digital camera, were hit and miss. I was able to recover about half of them fully. Fortunately, all of the pictures that were of any real value had been backed up offsite (like wedding pictures, of which there must exist a dozen DVDs with friends and family). The ones that I didn't have backed up were the scans from film, and most of those were unrecoverable. The ones that were recoverable, of course, had no filenames -- and my whole sorting system is based around file names. To go through and find/rename each image would take longer than re-scanning them. Bummer, but not the end of the world.

My ripped music collection was almost a complete loss. While RMF was able to recover most of them, at least partially, many of them were only partially recovered. I had several thousand songs with less than 1 second length -- obviously bogus. Again, it isn't the end of the world -- I'm just not looking forward to re-ripping 30GB of music from my archival storage of CDs. I'm honestly considering just downloading someone else's rips, because it will be faster and easier than doing it myself.

Archives, btw, are great for file recovery systems. For whatever reason, every zip/rar/tgz on the drive survived. Moreover, all the files inside archives survived, and they kept file structure, which really helps.

So the short version is that SlowToady was right -- the best answer is just to wipe the drive and start over fresh. I never figured out what the mis-reported size issue was, but it came up correctly this time in PQMagic, partitioned cleanly and everything. I'm now looking at half-TB external drives, and plan on purchasing one for backup soon.

Thanks for the help, everyone.

Dan

[Joeaksa]

Dan,

Glad to hear it.

One point, files and data stored on a CD or DVD is not good "forever"... Pls store things in multiple places if they are important.

Joe