I can't promise this will help, but you never know.
I originally set up my TC via ethernet to do the original full backup, but since then I've been backing up over ethernet. Last night, I plugged my MacBook back into the ethernet to resolve a problem on another part of the network and left it plugged in overnight. This morning I came down to the 'cannot mount disk image' error; even after I'd unplugged the ethernet and tried wireless connections. Time Machine did see the drive and let me roll back, but no backups had been made for a few hours. So I knew the archive was okay.
The first thing I did was check the TC drive in Disk Utility - this takes a VERY long time and seems to stall about 3/4 of the way through - it hasn't crashed, it's just lying when it says it'll be another 3 minutes or so. I found no errors on the TC, but it might be worth checking just in case.
I was able to get it working again.
Basically the link to the TC's network drive had been lost during all my cable swapping. I needed to go into System Preferences -> Time Machine, then [Change Disk...] and select the TC's drive from the list of available volumes, then [Use for Backup]. That remounts the TC's drive and makes it available to Time Machine.
You can now start a backup. The first time you do this it will take a while to prepare the back-up (and Finder will be busy indexing the drive as well), but hopefully that should get you working again.
I, too, have the "could not be mounted" error. So in the middle of fiddling with it today, I get the software update from Mac that installs all new Time Machine and Airport software AND even new firmware for the TC. So I'm thinking, ah ha, that will solve all my problems...maybe even my diabetes.
Ah, but nooooooooooo. Same freaking error after installing all the new stuff. Danggggggggggg this TC has been more trouble than any hardware or software I've ever installed...and I've been installing on Mac since 19freaking84.
I've been battling with the same "backup disk image could not be mounted issue" for the last few days.
I just resolved it by deleting the incomplete backup disk image file on my Time Capsule disk. Works great so far!
My iMac logs out automatically after a period of inactivity, so that may have caused the intitial backup disk image to cut out causing a corrupted file. Whatever the reason it, seems like just deleting the file worked.
Be interested to hear if this works for anyone else also.
After trying various options, I also found that I could get the backup to start (and avoid the "unable to mount disk" error) by deleting the incomplete disk image from the TC. Thanks for the tip.
The other option is probably to use the Disconnect All Users button in Airport Utility -> Disks -> Disks. This worked for me thanks to the hint about an open Windows user.
I have been having this same problem with my Iomega 500GB drive connected via USB to my macbook pro. I got a complete backup done and Time Machine worked for about a week and now I get the error "The backup disk image could not be mounted." I am very frustrated...I've restarted and re-booted both the computer, and the hard drive multiple times still without any luck. I can access other files on the drive so I know it is mounted to the computer correctly. Please provide help.
I also have a sneaking suspicion that the apostrophe that TM puts into most sparsebundle file names may be causing a lot of these issues....but have not yet had a chance to test it.
I'm also having this issue. "The Backup Disk Image Could Not Be Mounted." The fact that so many people are having this problem leads me to believe that it may happen again... What good is a backup device that produces corrupt backups? If you're thinking of buying a Time Machine, think again!
Same problem here. Except to make it worse, my MacBook crashed. Thinking, ahh, Time Machine has been sucessfuly backing up to TC I would be fine. Nope. Booting up from Leopard CD >utilities>restore ... it wouldn't allow me to open the disc image. Spent hours and hours with several different technicians from Apple with no clear cut result. They think the disc image might have ben corrupted. This is so frustrating. And I too have been with Apple like forever. Still willl be. But I'm sure ticked off about this.
