Disk Image Opening Error

[SeniorChief]

I am running Yosemite. I received a message telling me that I had a hard disk going bad. I tried disk repair. No joy. The system said that it could not repair the volume and that I should back up my files and reformat the volume . So I created a disk image of the disk onto another disk. I reformatted the first drive and attempted to restore the image. It won't mount. It is over 800GB. After 4 - 5 hours, it finally stops and says it could not be scanned. Is it because of it's size? I have a 2011 iMac 27" Intel i5. 8GB RAM. Am I doing something wrong? It there any way to save my data? I would expect something like this from Windows, but my iMac has been so solid.

 

[harryb2448]

G'day and welcome to the forum.

'I reformatted the first drive' ~ does that mean you have reformatted the internal hard drive? If so the problem is you should have backed up the entire contents to an external drive, and if you had cloned it, transfer it back to the internal after formatting.

Or have I got it wrong (yet again)?

You have not supplied computer details or operating system which is vital. If using OS X.7 or later, you should have used Recovery mode to run Repair Disk. Here is how Recovery works:-


http://www.tekrevue.com/tip/mac-startup-options/

 

[SeniorChief]

Hello Harry

Thanks for the reply. My computer stats were in the posted but I'll repeat them here: :-D
27" iMac 2011 Model i5 with 8GB RAM. 1TB internal drive

The internal drive is 1TB partitioned to 750GB Mac Yosemite and 250GB BootCamp
Three external USB drives, all 2TB each. First drive has two volumes:
External 1 & Time Machine (1TB each)
Second Drive one volume:
External 3
Third drive: one volume
External 4.
(I took External 2 which is another 2TB USB drive off and put it on my Mac Pro Dual G5 I use as a file server.)
The fist external drive (External 1 & Time Machine) has been reformatted and Time Machine remounted. External 1 is now blank.
The image of External 1 (External 1.dmg) is on External 4. The internal drive was not used. External 3 is empty as well.
I have been a DOS/Windows user for 30 years.
I have only been using a mac for a few years and have not mastered it.
Any ideas now on how to remount my External 1.dmg and recover the data? Thanx in advance!

 

[harryb2448]

As I feared if external 1 has been formatted, the contents may well be gone. If it is very valuable information you might like to try a recovery service, but this can run into thousands. You mention a Mac Pro G5. No such beast.

It is either a G5 Dual Core late 2005 model with one optical drive door on the front, or a 2006 or later Mac Pro with two optical drive doors. Should it be a G5, be aware that any operating nsystem later than Leopard OS X.5 will not run - Intel only.

Sorry about missing the specs. Too early for me some mornings Down Under as I get older lol!

 

[SeniorChief]

I have the dmg file.

I have the dmg file created off the External 1 drive. Is there another way to open the dmg file?

 

[harryb2448]

Not my cup of tea as it were but it is an awful large .dmg file. Woulad have suggested cloning, but that is a little late now. Do you get an unsupported file system message at all?

PM Administrator vansmith and see if he can help. Click on his name in a thread, down to PM and proceed.