Disk Utility stuck on 'verifying' while restoring

CoraMandel wrote:

Thanks for responding, but it doesn't get me out of my current dilemma.

You have options:

Quit the process

Force quit the process

Force unmount the external drive

Quit apps on Mac - Apple Support

How to force an app to quit on your Mac - Apple Support

Unmount a disk set or disk member using Disk Utility on Mac

From Terminal.app you can see unmount (or umount)

man diskutil unmount | more

or paste into your browser window:

x-man-page://diskutil 

CoraMandel wrote:

I was making a copy of one 3TB external hard drive to another identical drive using the 'restore' facility on my MacBook Pro. There's around 2.2TB of data on the source drive and the other drive was full. I used 'restore' because I thought this would be faster than erasing the target drive and copying the data to it. But I think I was wrong. The process began 24 hours ago and the 'verifying' progress bar hasn't moved all day. The lights on both drives continue to blink, so it looks like something is happening in there. But maybe not. Both drives have been unmounted for the restoration operation so I can't look into either of them. Disk Utility can't be shut down either. I'm hoping that the actual data copying has been successful and this is just a last minute glitch, but obviously I worry that if I shut down the Mac and disconnect the drives, I may do irreparable damage to the data. On the other hand, is it likely the source drive will be OK and only the target negatively impacted?

Any advice or solutions?

I would use some thing like Carbon Copy Cloner to clone the drive.

My understanding is the DiskUtility >Restore is problematic

CoraMandel wrote:

That did the trick. Thanks. The source drive was in tact but the target drive was unreadable and had to be reformatted. But it now seems to be receiving transferred data through ChronoSync (on a trial offer) which I shall now set up to synch daily.

Phew!

God computing CoraMandel, appreciate the feedback.