Backup-ing to Time Machine: "The backup disk image could not be created."

I just upgraded to a MacBook Pro 2021 M1 Pro with Sonoma. On my previous MBP mid 2015 I have been running backups through my Airport Extreme to a USB hard drive. That always worked great. Since I switched to my new MBP I am getting this error message:


Time Machine couldn't back up to [name airport extreme]


When I click on "details" I am getting these messages:


Time Machine couldn’t complete the backup to [name backup]

The backup disk image could not be created.


I checked the following things already:

  • Connecting the USB hard drive straight to my MBP and running the backup. That worked.
  • Erasing the hard drive and setting it up to AFPS and Mac OS Extended.
  • Then when I connect the drive to the Airport Extreme, I am getting the error message again.


What am I missing?

AirPort Extreme

Posted on Dec 2, 2023 11:34 AM

Reply
4 replies

Dec 19, 2023 6:25 AM in response to svanwessem

svanwessem wrote:

I just upgraded to a MacBook Pro 2021 M1 Pro with Sonoma. On my previous MBP mid 2015 I have been running backups through my Airport Extreme to a USB hard drive. That always worked great. Since I switched to my new MBP I am getting this error message:


Connecting the USB hard drive straight to my MBP and running the backup. That worked.

• Erasing the hard drive and setting it up to AFPS and Mac OS Extended.
• Then when I connect the drive to the Airport Extreme, I am getting the error message again.

What am I missing?



I would do what works.



Time Machine w/ todays "MacBook Pro 2021 M1 Pro " is looking for GUID / APFS




The current stable release of Sonoma including bug fixes, security updates is macOS 14.2

Keep your Mac up to date - Apple Support

Keep your Mac up to date - Apple Support



Dec 19, 2023 6:52 AM in response to svanwessem

When Time machine attempts to back up to a drive that is on another computer, the data are not stored in a 'regular' Mac file. Instead, a 'sparse bundle disk image' (a Volume inside a file on the backup computer) is created. This has always been true whether the backup computer was a Time capsule, Network attached Storage system, or another Mac.


what SHOULD be happening is that you should be offered the ability to "inherit" the old backup. then you can just add on to it.


But if that does not happen, that drive must now create a NEW very large sparse bundle disk image file. There is likely not enough space to create that new file, but the error messages are not clear because the process is performed indirectly.


If you really want the time capsule as your backup destination, you may have to research how to "inherit' you old backup, -OR- erase the time machine disk.


My recollection is that NO options for drive format are provided, it does the Erase its way. I thing Airport Utility might be required.

Backup-ing to Time Machine: "The backup disk image could not be created."

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