Apple - Creating an image from a Time Machine backup – "Operation Cancelled"

For some reason, this only works via command line using the hdiutil tool.

First, open Disk Utility, right click the source drive (the Time Machine volume), and choose Unmount. Do not eject it!

Then, open a Terminal window, and enter:

diskutil list

You should be able to locate your volume. For example, in my case, it was listed as follows:

/dev/disk5 (external, virtual):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                  Apple_HFS Backup Apollo          +500.0 GB   disk5
                                 Logical Volume on disk4s2
                                 Unlocked Encrypted

Copy the identifier, /dev/disk5. This is what we want to convert into an image.

Then, run the following command, which will create an encrypted image of the source volume:

hdiutil create /Volumes/Data/Backup.dmg -encryption -stdinpass -srcdevice /dev/disk5

Here, /Volumes/Data/Backup.dmg is the target file. Change it according to your needs.

You need to use sudo to run this command (left out for security reasons), so when you're sure it's correct, run sudo hdiutil create ….

After hitting Enter, you will be asked for an encryption password. This takes a while, but it works:

Elapsed Time:  7h 15m 52.227s
File size: 293424025874 bytes, Checksum: CRC32 $753B4175
Sectors processed: 976562496, 968645649 compressed
Speed: 18.1Mbytes/sec
Savings: 41.3%
created: /Volumes/Data/Backup.dmg

For more options, run man hdiutil.

This could be an OSX security issue. Try this:

  1. Open System Preferences
  2. Choose Security & Privacy and then click on the Privacy tab
  3. Select Full Disk Access from the list on the left
  4. If necessary, click the padlock icon to allow changes
  5. Click the + icon and add Disk Utility to the list of apps by browsing to it (/System/Applications/Utilities/Disk
  6. Re-open Disk Utility and try making the image again.