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Can't Open my Backup DMG years of data gone

Okay I'm going to try to describe this in as much detail as I can and hopefully someone out there can help. I'm using a Mac Pro that has one harddrive in it, 250gb. I also have a Macbook Pro. I also have an external USB drive that's 250gb, and it's partitioned in 2 parts, on is about 200 and the other is 50. I can NOT boot from this drive.

A couple of days ago I decided I would back up my Mac Pro in anticipation of Leopard. So I booted into the Tiger Install disc that came with my computer, and used the disc utility to create a restore image of my entire Harddrive, using the default settings. The image is saved to my external drive.

I got Leopard on Friday and installed it using a clean instal, erasing everything on my computer and installing it fresh. The install went fine and Leopard works magically on this machine. I decided it was time to start bringing my files over from my image I had created, so I attached my drive and opened the DMG, but it wouldn't open, giving me error -4960. PANIC ENSUED. I also tried to mount it on my MacBook Pro which is still running Tiger and I got the same error!

The next day (yesterday) I called Apple, and the man I spoke with told me the reason why it won't mount is because its a raw restore image and what I'll have to do is restore it using the disk utility again. That made sense to me. This morning I tried restoring the image with both the Leopard utility and the Tiger one as well (booting off the install DVDs, that is), but no matter what I do, I get the same error -4960!!

So at this point I'm basically shattered. I live on my computer, it's my whole life (I know that may sound sad haha but it's the truth). This is like having my house burn down, and on top of that, the IRONY of the situation is just too much. The whole reason for upgrading is to get Time Machine.. Ugh. Anyway, Im starting to run out of ideas here. I think maybe it could be because my external drive is a piece of crap or something, so I'm currently copying the thing over to my internal drive and I'll try that. Other than that, I'm thinking the image must be corrupt or something, does anybody know any hardcore tools that could be used in such a situation? Any terminal-fu that could possibly fix this whole problem? I did use data recovery software on the drive yesterday and managed to get a few things, I think,, but I havent really looked through them and it's really not the same as having the files themselves, you know? But I guess it's something.

So yeah, if ANYONE has any ideas on what to do, you have no idea how thankful I would be to hear it.

Jason

touch fuzzy, get dizzy

Posted on Nov 4, 2007 9:20 AM

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Posted on Nov 4, 2007 10:06 AM

I'm very sympathetic to your situation and have been investigation error -4960 for you. These aren't specific answers but they might point you in the right direction, on your own, or communicating with Apple. Both of these, though unrelated, suggest the problem and solution is related to the User account. Just a hunch, but I'd try opening the DMG from your Guest Account. Keep bugging Apple, too!

http://docs.info.apple.com/article.html?artnum=93311

http://www.tech-archive.net/Archive/Mac/microsoft.public.mac.office.entourage/20 05-02/0052.html
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Question marked as Best reply

Nov 4, 2007 10:06 AM in response to The Shad Guy

I'm very sympathetic to your situation and have been investigation error -4960 for you. These aren't specific answers but they might point you in the right direction, on your own, or communicating with Apple. Both of these, though unrelated, suggest the problem and solution is related to the User account. Just a hunch, but I'd try opening the DMG from your Guest Account. Keep bugging Apple, too!

http://docs.info.apple.com/article.html?artnum=93311

http://www.tech-archive.net/Archive/Mac/microsoft.public.mac.office.entourage/20 05-02/0052.html

Nov 4, 2007 11:01 AM in response to nerowolfe

Okay, well I tried logging in as the Guest on Leopard and opening it, but no dice (I also did a Get Info on it and made sure everyone had Read/Write access to it), even tried doing a chmod on it but still it won't open/mount.

nerowolfe, what do you mean? The tiger box I have is my MacBook Pro, and when I connect the external drive to that machine, I get the same error that I get with this Mac Pro. Those are the only 2 Macs in the house. I won't modify the image, what do you suggest I do to it (or, a copy of it I should say) to fix it? I'm thinking trying diskwarrior, I hear good things about that.

Thanks for your support guys/gals I really appreciate it!

Nov 4, 2007 11:54 AM in response to Charles E. Flynn

okay, I just tried that from the Leopard installer disk utility and it says it's unable to scan, Error -4960. I tried several other options from the Images menu, they all failed and gave me the same error.

When booted into OS X, I used the Disk Utility and tried a few things, looking at the log it says:
[DUDiskController viewablePartitions] expecting DUDisk, but got nil

Which leads me to believe something in the dmg fileheader is missing (I don't know how this all would have happened. When I made the image in the first place, it worked without error!). I'm a Computer Science student, does anybody know where I can find any solid information about the DMG format? Does Apple provide a spec or anything?

Also, both DiskWarrior and Pacifist failed to open the file. What about using dd (the unix utility) to restore it? I'm thinking that would not work... Thoughts?

Nov 4, 2007 11:59 AM in response to The Shad Guy

The Shad Guy wrote:
okay, I just tried that from the Leopard installer disk utility and it says it's unable to scan, Error -4960. I tried several other options from the Images menu, they all failed and gave me the same error.

When booted into OS X, I used the Disk Utility and tried a few things, looking at the log it says:
[DUDiskController viewablePartitions] expecting DUDisk, but got nil

Which leads me to believe something in the dmg fileheader is missing (I don't know how this all would have happened. When I made the image in the first place, it worked without error!). I'm a Computer Science student, does anybody know where I can find any solid information about the DMG format? Does Apple provide a spec or anything?

Also, both DiskWarrior and Pacifist failed to open the file. What about using dd (the unix utility) to restore it? I'm thinking that would not work... Thoughts?


Has Apple support been helpful? They have lots of tools at their disposal. If the dmg is corrupted, as you note it might be, most of the data are still recoverable. I am sure that somewhere at Apple they have dmg extraction tools for exactly this purpose.
I assume the dmg is quite large, but might it be possible to burn it to a bunch of DVDs?
Also, if you right click the dmg and select "get info" does the size seem reasonable?

Nov 4, 2007 1:04 PM in response to nerowolfe

Well aside from the original answer they gave me of "just restore the image back to the harddrive", I haven't been talking to them, but you're right, it would be a good idea to call them back about it.

I've checked the size of the DMG and yes it is very large, nearly 120gb. Right now I've got two copies of it, one has been copied over to my internal disk and one is still on the external drive (and of course, neither will mount). So I will call Apple back and see if they have any tools that can assist me. I'm glad I know as much as I do about computers, so hopefully I can give them a hand (which would be a lot nicer than me having to reverse engineer the DMG format because I can't seem to find anything about it anywhere).

Nov 4, 2007 2:30 PM in response to The Shad Guy

The staff at the Apple Store in Providence once told me not to attempt to restore disk images while booted from the Mac OS X DVD. It often does not work.

I suspect that if you choose "Scan image for restore" while using Disk Utility from your hard drive, you will get the same error.

Use the Console application to check your console and system logs. See if this is the error description:

CoreDragCreate error: -4960

If it is, put the entire expression into quotation marks and search for it at Google.

Nov 4, 2007 4:00 PM in response to Charles E. Flynn

Okay well Googling that error didn't really turn up any help. And I've called Apple again but they aren't being any help either really, saying it's a lost cause.

But I know it's just a messed up header on the DMG. I'm looking for some documentation on the format so that I can fix it myself, does anybody happen to know where I could find anything? I've also emailed the Apple Dev support to see what they have to say, so I guess I'll hear from them tomorrow or something.

Nov 4, 2007 6:12 PM in response to nerowolfe

The man page for hdid, used to manipulate disk images, states “Unfortunately, read-only device images made from mounted journaled volumes will not mount because the journal can't be replayed.

Does anyone know whether that problem has been fixed? I have always been puzzled about why the Help in Disk Utility gives no step-by-step instructions for creating a disk image of a bootable volume, and for restoring it.

Nov 4, 2007 6:56 PM in response to nobody loopback

Okay I've done that and I get lots of output to both stdout and stderr, and also I get a whole dump of the image.

I've already looked at the image wiht a hex editor and by golly, my files are in there, I've searched for my name and it's turned up in text files, so I know the data is all there and good.

Perhaps you can email me "nobody lookback" because you seem to have a great deal of technical knowledge and I don't exactly want to spam the Support Boards here, you know. That is, if you don't mind. I'm really glad for your help so far, you and everyone else!!!

my email is i.jasonbrennan AT gmail

Can't Open my Backup DMG years of data gone

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