Disk Utility Will Not Copy Time Machine (Mojave only)

PianoPro

macrumors regular
Original poster
Sep 4, 2018
232
118
I tried to copy my Time Machine backup files from a 2010 Mac Pro internal drive to a USB drive. It works using High Sierra, or from the Recovery mode (boot with cmd-R). But it will not work from Mojave.

Process -

Using Disk Utility select the destination drive, then click Restore, choose the Time Machine drive in the drop down menu, and click Restore. Disk Utility responds:

Source volume format on device [the time machine drive] is not valid for restoring
Could not validate source - Operation not permitted

This is normally the easiest and fastest way to copy a Time Machine backup because Disk Utility Restore uses block-mode copying between partition volumes. Dragging the backup files from one disk to another takes days to copy because literally millions of links have to be read, prepared and then copied. Literally days for a large time machine file. I know that is the Apple recommended method but using Disk Utility has always worked much better and faster.

As I said I just tried this using High Sierra (worked) and from the Recovery mode (worked). But Mojave doesn't work. Any ideas on how to make it work or why Mojave doesn't like the Time Machine format?

(I can go into Time Machine and restore files from Mojave, so its only Disk Utility that doesn't like the Time Machine backup files)
 

eelpout

macrumors regular
Oct 30, 2007
236
6
Silicon Valley
Running into the same issue while upgrading to a couple drives of a bigger capacity. The procedure worked fine with one drive which has a bunch of images on it. When I tried it with the drive that has my Time Machine "Backups.backupd" folder on it, I received that message.

I can't figure it out. Somewhere, might have been some developer forum, I read to make sure there was a partition first on the target drive that was identical in type to the original, which it is, so that's not it. In my case I'm sure it has something to do with the Backup folder.

If you figure anything out, please let us know.
 

PianoPro

macrumors regular
Original poster
Sep 4, 2018
232
118
Running into the same issue while upgrading to a couple drives of a bigger capacity. The procedure worked fine with one drive which has a bunch of images on it. When I tried it with the drive that has my Time Machine "Backups.backupd" folder on it, I received that message.

I can't figure it out. Somewhere, might have been some developer forum, I read to make sure there was a partition first on the target drive that was identical in type to the original, which it is, so that's not it. In my case I'm sure it has something to do with the Backup folder.

If you figure anything out, please let us know.
I never figured it out. I finally just started a new time machine on an external drive and now let time machine ping-pong back and forth between the internal and external drives, so newer stuff is backup'd up twice but the older time machine stuff is still only on the internal drive. Seems it's a Mojave problem since it works in High Sierra, so I also sent a bug report to Apple but never got a response.
 

eelpout

macrumors regular
Oct 30, 2007
236
6
Silicon Valley
Yeah, after two attempts at this and 24 hours of copying a Backups folder that mysteriously inflates its size to no end, I'm just going to start over with a new backup. Something is definitely broken. :)

I'll file a bug report too about "the Source volume format not being valid" error in Disk Utility. They need to at least give a better explanation of what is wrong.