Time Machine: "backup disk image could not be created"

For some people, Time Machine won't let them backup their computers to a network drive. Instead, it gives them an error saying it can't create the backup disk image.

Apple Discussion poster "whateverwerks" writes:

"Set up my new time capsule day and it's working great. Now that I've got everything sorted out, I'm ready to do the initial time machine back up on it. I went into preferences, changed the backup location to my TC and clicked 'back up now'. Very quickly I get a message that the backup failed: 'Time Machine Error - The backup disk image could not be created'."

The problems occur when there is poor network communication between the Time Capsule and the computer. This happens for a variety of reasons and it can result in improper Time Machine connectivity as well as the device not mounting on the computer and invalid reporting of the space available on the drive. To remedy the issue, make sure the network names are correct and try resetting the Time Capsule.

Fixes:

1. Reset local machine name

If the computer's local network name is empty, Time Machine may have a problem connecting to the Time Capsule. This can be easily fixed by going to the "Sharing" system preferences and ensuring both the "Computer Name" is entered properly, as well as the local network name that can be edited by clicking the "Edit..." button. You might try simplifying these names as well, such as removing spaces and punctuation marks if used.

2. Simplify Time Capsule names

In the Airport Utility, make sure that the Time Capsule and local network names for the Time Capsule are eight characters or less, and do not have spaces, apostrophes, or underscores.

3. Enable "Show Connected Servers on Desktop"

If you do not have the Finder set up to show connected servers on the desktop, you will not see the Time Capsule mount. Go to he Finder's preferences and check the box that says, "show connected servers on desktop".

4. Power cycle networking devices

For Airport Extremes, Time Capsules, and other devices that are on the same network, power them down and unplug them for a few minutes, then restart them and see if that helps the situation. Sometimes settings on these devices can become corrupt and a restart should refresh them properly.

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