Time Machine says 'disk image failed to mount'

I had the same problem with 10.5.2. Time Machine just stopped working. There is a big xxx.sparseimage file on the backup disk, but I can't mount or verify it using Disk Utility.

I had this happen once. After rebooting the TC and my Mac, it has worked beautifully ever since backing up 3 Macs on the network.

I have the same problem. My Air backs up to TC fine on wireless but I have an ethernet connection to my Macbrook Pro (am frightened of the back up time if I use wireless) but I get (disk image failed to mount.) TC light is green, I am off wireless on the Pro. I use an airport extreme for the network and have the TC connected to the network. I have set the TC to Off(bridge mode). I have tried rebooting. What else can I try?

I've had the same issue, it was working fine, then stopped doing auto backup. I just went into airport utility and restarted the tc. I rebooted mac and then I got a message my network was not found. I re-established connection (entered password) and then started a manual backup. It is currently backing up - hopefully this will solve the issue.

I just encountered something similar. Have been backing up a MacBook Pro wirelessly and a MacBook wirelessly for about 3 weeks to the same drive. I'm not using a Time Capsule, but an external HD connected via USB to an Airport Extreme.

The MacBook can still backup. I can also enter Time Machine and look through the old backups on the MacBook and everything is fine.

The MacBook Pro can't mount the disk image either when attempting to backup, or when Time Machine is invoked. Fails when wired via ethernet, and wirelessly.

Both machines have all of the latest 10.5.2 updates and started backing up with Time Machine within a day of each other.

same thing here. it has been working for a couple of weeks and now it doesn't mount the disk image. the last time this happened, the helpful advice i got from Apple support was to delete the disk image and start over. Isn't this the entire POINT of TimeCapsule? why does it corrupt its own disk images? it must be some sort of serious corruption if the image cannot be mounted. it doesn't even mount from the finder.

Reboot the computer if it still fails to mount then you need to repair the disk in Disk Utility. That should fix the problem till it happens again.

I have had the same problem; and the image which fails to mount causes the MacBookPro (which backs up to that image) into a kernel panic with the grey screen of death. Oddly, five other Macs which back up using Time Machine to the same Time Capsule have no problems continuing to back up. The sparseimages associated with those other 5 will mount no problem.

I cannot get Disk Warrior or Disk First Aid to "see" the unmountable sparseimage, so I can't repair it.

Same here.

1) I've got time machine over time capsule.
2) It worked for two weeks.
3) Until the backup failed with "time machine cannot mount disk image"
4) I've checked the sparsebundle disk image with the apple disk utility. Result:
= Indeed, the disk image is corrupted (incorrect block count).
= But CANNOT be repaired due to 'invalid sibling link'

CONCLUSION: The time machine/ time capsule failed in its core function. To provide backup!
= (So much to: 'because apple produces hardware and software...')

SOLUTIONS ?!:
1) I cannot understand how other people with this problem put up with 'deleting the sparsebundle' as a solution?!
= It's not a solution, you are loosing all the different time-snapshots and you are without backup for a certain time!

2) Using 'disk warrior' (Cost: 100USD which apple most likely is not going to refund me!) does repair the disk image, although with (in my case) hundreds of 'overlapping' thus lost files...

CONCLUSION: my confidence in the apple time machine solution is completely lost. I will start to use rsync to make conventional backups. And use time machine as what it is: a TOY.

--
I would love to live in a simple black&white world. Microsoft bad, apple good... but it seems that the bigger the company the less it cares about individual customers and in this case the value of our data.

I got the same error message in Disk Utility.

How did you get Disk Warrior to even recognize the disk image? It would not mount, and so, Disk Warrior did not even know it existed, so it could not repair it.

Follow up to previous post...My TC said preparing for a good 2 hours, it never did anything else. I called tech support, and finally got someone on the phone that could help me (thanks dave). He had me erase my TC through airport utility and it has worked fine ever since. Lucky me, my mac is as new as my TC and erasing it wasn't a big deal. He did say if I couldn't have done that, there is another way to get it to work again. good luck!

Same crap here, but with a twist. I've had two computers backing up to Time Capsule since I got it five weeks ago. My laptop just ceased to backup earlier this week, presenting me with two error messages at once:

1. Disk Repair: The disk "Backup of Cory's MacBook Pro" was not repairable by this computer. It is being made availble to you with limited functionality. You must back up your data and reformat the disk as soon as possible.

2. Time Machine Error: The backup disk image could not be mounted.

However (and this is the twist), the second computer I have using the Time Capsule continues to back up without issue. So what do I do? I've tried restarting via the Airport Utility to no avail. I will try a hard reboot next.

This is rather sad and ironic really; a backup system that fails in less than five weeks.

Well I just use Apple's Disk Utility in the utilities section and so far it has always resolved the problem, but reading this thread apparently some people are unable to repair the disk through the apple utility.

I resolved my issue. What I did was to go into the Time Machine System Preferences, click on "change disk...", select "None", to turn time machine off.

Then I turned Time Machine back on by repeating the same procedure and when selecting a disk for Time Machine, selected the drive that had the disk image that couldn't mount.

I connected the laptop via ethernet, and the next backup took a considerable amount of time, over an hour, but once I allowed it to finish, everything has been fine since. All previous incremental backups are available.

I suspect the original issue has something to do with putting the laptop to sleep during a backup, but I don't really have any proof of it. I now avoid shutting down or sleeping in the middle of a backup.

Me Too!

My 1TB Time machine continues to work fine with my iMac and Mac Mini but my Macbook gives this same error.

How do I get the Macbook to work without stuffing up the backups of my other two Mac's??????