Unable to restore from a backup on external drive

Question

Level 1

9 points

Unable to restore from a backup on external drive

I'm trying to migrate my old mac content to a new Mac. No luck with this simplest of tasks.

I had a setup where an external drive was connected to the USB port of an AirPort Extreme. Time Machine backing up to a disk on this drive over WiFi just fine.

Using Migration Assistant on the new Mac, same network, it can find the AirPort Extreme -connected backups, but the restore process over WiFi is so slow it stalls every time after hours of trying. Tried twice, gave up and quit the Assistant as the progress counter didn't move for hours, didn't even show a transfer speed anymore. At best it was 2Mb/s.

So I take the external drive and connect it to the new Mac's USB-C port. Shows up in Finder just fine, I can even navigate to the backup bundle file on the disk. Problem is, Migration Assistant cannot find that backup no matter what I do. Just the new Mac and "looking for sources" appears.

How can I restore my backup from the drive now directly connected to the new Mac??

Posted on Sep 1, 2020 11:34 AM

Reply

Answer 1

Top-ranking reply

kylieo Author

Level 1

9 points

Sep 4, 2020 7:13 AM in response to leroydouglas

So, finally success. Went by the worst case scenario option.

CMD-R on restart
Erased and reinitialized the parent drive
Chose the option to restore from TM backup - this assistant found it just fine from the USB connected external drive, unlike the Migration Assistant
The restore of a 128Gb setup took 9hrs. Not exactly expected result, but it completed and every seems to be right where it's supposed to be.

Lessons learned:

TM backup to an AirPort Extreme connected external drive over WiFi works fine over time, but forget about trying to restore over WiFi
The Migration Assistant does not find the backup on external drive. The initial setup assistant or whatever it's called, finds it just fine. No idea why.
Disk Utility isn't exactly user friendly, nor are the Apple Support articles describing its usage. Screwed up here, apparently.
The restore process seems ridiculously long, prepare for that if you have to start fresh

Thanks Leroy.

Reply

Answer 2

kylieo Author

Level 1

9 points

Sep 29, 2020 11:56 AM in response to kylieo

Answering myself that the backup disk had to be re-selected in TM, then the prompt to inherit backup history came up.

What followed was a four-day update of the backup over wifi until the first backup was complete. Considering very few files had changed and no big new ones added, that’s kind of ridiculous.

Reply

Answer 3

Sep 1, 2020 1:59 PM in response to kylieo

kylieo wrote:

Additional detail: After cmd-r and full disk erase I was able to get the “restore from time machine backup” option in the boot menu to pick up the backup on connected external

drive. Then had to make a complete guess between destination drive “Macintosh HD and Macintosh HD - Data”. Chose “Macintosh HD”. After about 30mins into the restore process this came up and I gave up hope.

https://discussions.apple.com/content/attachment/91fb67d4-ddae-4bd8-bee3-4150268ead15

When you did your "cmd-r and full disk erase" did you erase/format/initialize the parent drive?

From Recovery >Disk Utility>View>Show All Devices> the parent Drive

Drive level

Container level

Volume level

MacOS Catalina should look like this if done correctly:

About the read-only system volume in macOS Catalina - Apple ...

Reply

Answer 4

Sep 1, 2020 2:20 PM in response to kylieo

kylieo wrote:

Not exactly. I didn't realise to change the "View" option from "Show only volumes" to "Show all devices".

Currently, after the OS reinstall completed, it looks like this. No idea what the faded out volume is now.

https://discussions.apple.com/content/attachment/62aae76b-6320-492e-91fd-8192d6680687

You can increase the size of that side bar for a better look, by grabbing the divider and drag it larger

You can try simply deleting that extra (empty) data volume— then try again your restore from backup and see if it takes. It could be all is well if your user data is all there as expected(?) but if I am tracking this correctly your restore did not complete.

Worse case scenario is you have to redo the erase/format/initialize of the parent drive with the 'correct procedure' to straighten thing out—and then do your data restore again.

Reply

Answer 5

Sep 1, 2020 1:03 PM in response to kylieo

What is the current maOS on your "new" Mac?

What is the macOS on your backup?

You can not restore or migrate from a newer macOS to an older macOS...

Just maybe the "new" Mac needs to be upgraded first—since you make no mention of what exact Mac, what exact macOS

Reply

Answer 6

kylieo Author

Level 1

9 points

Sep 1, 2020 1:28 PM in response to kylieo

And “the Mac” btw is a late 2018 Macbook Pro which had it’s entire logic board replaced by Apple service center. Data lost as well obviously. So the “new Mac” is physically the “old Mac” with new internals.

Reply

Answer 7

kylieo Author

Level 1

9 points

Sep 1, 2020 1:34 PM in response to leroydouglas

Additional detail: After cmd-r and full disk erase I was able to get the “restore from time machine backup” option in the boot menu to pick up the backup on connected external

drive. Then had to make a complete guess between destination drive “Macintosh HD and Macintosh HD - Data”. Chose “Macintosh HD”. After about 30mins into the restore process this came up and I gave up hope.

Reply

Answer 8

kylieo Author

Level 1

9 points

Sep 1, 2020 2:13 PM in response to leroydouglas

Not exactly. I didn't realise to change the "View" option from "Show only volumes" to "Show all devices" upon initiating the erase.

Currently, after the OS reinstall completed, it looks like this. No idea what the faded out volume is now.

Reply

Answer 9

kylieo Author

Level 1

9 points

Sep 4, 2020 7:19 AM in response to leroydouglas

One final unclear thing is, do I now have to start a completely new backup and delete all the old ones? When the same external drive with the old backups is plugged back to the router, the freshly restored setup can no longer "find the backup disk", and the TM backup doesn't start.

My assumption was that since the original system was restored from a backup, it would automatically start using the same old backup just replacing it with new changed data.

Reply