Moving Time Machine to new external disk

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GyozoK Author

Level 1

13 points

Moving Time Machine to new external disk

Hi,

I work on macOS Mojave 10.14.6 with latest Security Update 2020-004.

I am following this article by Apple to move my Time Machine backup to a new USB disk:

https://support.apple.com/en-us/HT202380

My old Time Machine backup is on a 500 GB external HDD called "macOS Time Machine":

As you see above, 296,32 GB used on this drive.

Here it is important to know that besides the Time Machine backup ("Backups.backupdb" folder) I have 2 other folders on the source drive taking up 73,87 - 69,0 = 142,93 GB space:

So 296,32 - 73,87 - 69,06 GB = 152,49 GB is the size of Time Machine backup ("Backups.backupdb" folder).

So far I created a new 665,92 GB partition on the new external drive with Disk Utility (macOS extended, Case-Sensitive, Journaled, Encrypted):

Then dragged+dropped the "Backups.backupdb" folder to this new drive's new partition.

After a night of copying now I see this:

The copy window shows me that macOS copied 414,5 GB to the new drive already, but Disk Utility shows the used space only 344,58 GB. How can it be? (yes, I refreshed the Disk Utility window)

Also, on the first screenshot above I see that Drive Utility reports 296,32 GB is used on the old drive, so how could macOS have copied already 414,5 GB (and still copying) even considering that we know I have 2 other folders on the source drive that I do not copy over, so as we calculated: Time Machine folder needs to be 152,49 GB only that is to be copied?

Looking at the partition information is also pretty interesting:

Source partition (left side) has 3.163.830 files while the target (right side) has 7.208.732 files and growing!

How could this happen? Where are those 4 million more files come from?!

Also, the copy windows looks pretty weird showing "Copy 0 items to..." and not being able to calculate the size of the data to be copied: the "414,50 GB of 414,5 GB" numbers keep growing in parallel and the "About 5 seconds" keep stay forever "5 seconds".

What is wrong with this simple copy process?

How can macOS report so false numbers for a simple folder copy operation?

How can Drive Utility report bad numbers?

How should I move the Time Machine backup to the new drive then?

Thanks for any help in advance!

GyozoK

MacBook Pro 13”, macOS 10.14

Posted on Aug 8, 2020 4:36 AM

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Answer 1

John Galt

Level 10

155,150 points

Aug 8, 2020 7:02 AM in response to GyozoK

How should I move the Time Machine backup to the new drive then?

You devoted a great deal of time and effort into attempting to understand what's going on. As admirable as your efforts have been they will not help accomplish your objective. I suggest that you forget all that in-depth analysis and use Disk Utility's Restore function instead: Restore a disk using Disk Utility on Mac - Apple Support. It will finish in a few hours, at most.

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Answer 2

GyozoK Author

Level 1

13 points

Aug 9, 2020 7:18 AM in response to John Galt

Thanks a lot, John, for your advice! Sounds like a straightforward, easy solution. Thank you for letting me learn about it!

(Btw, it also was helpful to get familiar with the macOS built-in disk imaging/restoring feature, too.)

I will probably give it a try just to be experienced with it for the future. I make sure to mark your advise helpful now and if I succeed as a solution as well.

For now, as I needed to step forward quickly, I cancelled the native copy and downloaded SuperDuper! to see if that makes a difference. And that did the job much better:

As the screenshot shows, SuperDuper! found 3.167.833 files to be copied - pretty close to the 3.163.830 files that Disk Utility Info reported (although not exactly - another mystery why a software sees different than the OS itself???).

SuperDuper! simply copied these files over to the new partition after erasing and now I have exactly the same files on the source and target drives as far as I can measure for first sight. Of course, SD not only copied the Backups.backupdb folder but the 2 other folders as well that I can simply delete now.

Not to let us go sleeping well with these mysteries only, now when restarted my MacBook today and plugged in the New Time Machine drive only, it looks like macOS recognised it somehow and automatically set itself up to use it as the Time Machine volume - despite all guides that say: "After copying the old backup file to the new disk, select the new disk in Time Machine preferences"

And the last mystery for those who got this far with Apple: strangely now the new volume is reported as

"Case-sensitive, Journaled" (in Finder)
"Encrypted" (in Time Machine)
"Encrypted, Case Sensitive" (in Time Machine)

Last two are both within the same application! A total mix-up! Which one should you vote for now?

Looks like macOS may not even know about itself the basic things... just keep running somehow!!! Great job, Apple!

Conclusion:

after all it is just unbelievable that

Apple very straight guide shows a procedure that just does not work with ease and at all
macOS in 2020 cannot do such a simple copy operation properly (I have not met any system like this in past 35 years of working with and programming from C-64 to all major systems (Linux, BSD, Windows) today, even the good old DOS could copy files)
there is no proper explanation what is happening here, just workarounds - but what about all these inadequate behaviours?

I am quite new to my MacBook Pro and macOS but I am an IT pro, a SW/HW engineer and programmer for 35 years and anything I saw on screen today makes me asking "so why are there so many Apple users on this Globe?" Even the easiest basic task like copying files between volumes requires so much extra effort and workarounds from me to complete - even if following exactly Apple's very own guide how to do it :((

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Answer 3

John Galt

Level 10

155,150 points

Aug 9, 2020 10:22 AM in response to GyozoK

I don't know why they provide those instructions, and can only surmise they decided they are easier to follow. Seems to me using Disk Utility is just as easy to follow though, and as it says it results in an exact same completely identical duplicate. Time Machine won't even know the difference.

Besides, using the Finder to move backups from one drive to another will take an age.

I'd also use Disk Utility to determine the file format (case sensitive / encrypted / etc). It's reliable.

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Moving Time Machine to new external disk

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