How should I Copy Mojave from one hard drive to another?

Question

How should I Copy Mojave from one hard drive to another?

Hello,

I have two 2010 5.1 Mac Pros, each running Mojave.

I have used one of these Mac Pros for the last year or so for video editing. I've DL'd many updates for Mojave over that period of time and there has never been a problem.

Recently, however, (within the last week or so) I downloaded and gave permission to install an update to one of the Mac Pros, the one I use for video editing. As best as I can recall now, it was a security update for the OS and a security update for Safari. I gave permission to download and install both.

Something wrong happened with the installation, and I cannot boot that Mac Pro.

So I am going to pull the startup drive from the Mac Pro that no longer starts up and install it in one of the drive bays on the Mac Pro that works fine.

These two 2010 Mac Pros are very close to identical in terms of their hardware. They both have 96 GB of ram and both have Radeon VII graphic cards installed.

Here's my question.....

How do I copy the OS from the startup drive for Mac Pro that runs to the other drive for the Mac Pro that won't start? It seems to me that should be an easy copy process, just copy the "System" folder from one drive to the other. Am I right? Is there anything I should be careful about???

Many, many thanks for all comments.

Mac Pro

Posted on Jul 1, 2021 6:06 PM

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Answer 1

Top-ranking reply

Patrick Murphy Author

Level 3

533 points

Jul 2, 2021 10:05 PM in response to BDAqua

Greetings!

Well, I have my Mac back! Everything is working fine. As soon as I logged onto the mac I was offered the same update that I tried to install before, but since I got into a lot of trouble with that I think I'll pass.

I'm going to have to take a look at a backup system. I have 6 drives - 4 internal and 2 external, but I don't have any kind of backup system in place. I'll have to look into that for sure.

I'm very happy to get all of my hobby work back. I doubt I would have been able to do that on my own.

Thanks so much for your help!!!

Have a great day!!!

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Answer 2

Jul 1, 2021 6:13 PM in response to D.I. Johnson

Before you do that, try to boot into recovery and reinstall just the macOS. Don't erase anything.

About macOS Recovery on Intel-based Mac computers - Apple Support:

https://support.apple.com/en-us/HT201314

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Answer 3

Jul 1, 2021 6:19 PM in response to D.I. Johnson

OK....but I have a question.

Will "Cloner" allow me to just copy the OS? By using Cloner, would I risk losing files that are in the target HD that are supportive of FCPX?? Is there just one folder that I should copy? This part of the problem I have is confusing for me. I am worried that I would lose some files that have been installed over the last year on the Mac that no longer works. What do you think??

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Answer 4

Jul 1, 2021 6:49 PM in response to Patrick Murphy

Well, I think what I am going to do is just rename the System Folder on the drive from the Mac Pro that doesn't work any more, and copy the System File from the Mac Pro that does work onto the drive from the Mac Pro that doesn't work any more. I don't think I can lose anything by doing that, and I think it might fix everything. If it doesn't work, I'm OK with it.

I've pulled the drive from the Mac Pro that doesn't work and put it into one of the drive bays for the Mac Pro that works fine.

I think that might work. If it doesn't, I'll just clone the drive that works and put the cloned drive in the "broken" Mac Pro.

I'll report here if it works or not. Might be tomorrow before I can do it.

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Answer 5

Jul 1, 2021 6:57 PM in response to Patrick Murphy

Cloner will allow you to selectively copy folders and files, including those that are normally invisible to us users.

But copying the macOS alone is not as easy as copying a particular folder. If only!

Were I in you shoes, I would first make a backup copy of that drive just as it is.

Then I would install it into the good Mac Pro or via USB in an external case or using a USB drive cable.

Try to repair the drive using Disk Utility. If DU indicates that repairs are needed and then proceeds to repair the volumes and drive, then put it back into the other mac and see if the problem is fixed. If so, then done.

If not... then plug the drive back into the working Mac again and then restart the good MP into recovery mode and reinstall the macOS onto the corrupted bad drive, just the macOS, without doing any sort of erase. If all goes well that should fix you up.

This assumes that both Macs are running the same OS version - yes, I see both are running Mojave.

It also assumes that the drive in question is not failed, failing or otherwise compromised and it assumes that it's OS corruption that is causing the problem.

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Answer 6

Jul 2, 2021 6:16 PM in response to D.I. Johnson

Well, it's been an interesting day.

I was able to get my Mac Pro that had stopped working to startup by using another hard drive with Mojave. I ran Disk Utility on the drive that had stopped working, and everything came up OK.

All of my software is still on the drive that is apparently corrupted from an installation of a Mojave and Safari Update that went bad for some reason.

I'm tempted to just copy the software folder over to the hard drive that works, however …

I've downloaded a Mojave Combination 10.14.6 Combo .dmg file and I'm pondering whether to use that to re-install Mojave onto the drive that doesn't boot any more.

So, I'm torn and feeling uncertain about what to do.

What would you suggest???

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Answer 7

BDAqua

Level 10

245,393 points

Jul 2, 2021 6:21 PM in response to Patrick Murphy

I've downloaded a Mojave Combination 10.14.6 Combo .dmg file and I'm pondering whether to use that to re-install Mojave onto the drive that doesn't boot any more.

Exactly what I'd suggest but install it in Safe Mode from the good drive.

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