How do I copy my internal SSD to an external SSD?

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How do I copy my internal SSD to an external SSD?

I want to make a backup of my internal 256 GB SSD. I bought a 480 GB SSD and connected it via USB. How do I copy my internal SSD to the external SSD? This would be a bootable external SSD.

I tried Disk Utiliy > Restore. It gave me this error message:

The source volume cannot be restored because it has a broken seal
Could not validate source - Invalid argument
The operation couldn’t be completed. (OSStatus error 22.)

Then I tried Migration Assistant. This will only copy between computers (Mac or Windows), not from an internal SSD to an external SSD.

I downloaded Carbonite but I couldn't see how to copy an SSD.

What should I try next?

Posted on Oct 21, 2021 5:39 PM

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Answer 1

Oct 23, 2021 5:58 AM in response to Thomas Kehoe

I think an arbitrary and capricious problem with the Install, or junk leftover from a previous install attempt may be interfering.

I suggest you boot to the installer, use disk Utility to erase the drive by its immutable device-name (be sure you have selected the Physical disk, not just a Volume) and ERASE again.

then proceed to Install.

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Answer 2

Thomas Kehoe Author

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92 points

Oct 21, 2021 7:40 PM in response to Grant Bennet-Alder

No, my MacBook Pro is old. Mid-2014 15" Retina.

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Answer 3

Oct 22, 2021 7:33 AM in response to Thomas Kehoe

it may be time to back up a little and think about "what re you really trying to accomplish in making this copy? do you merely want backup, or do you want bootable?

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Answer 4

Thomas Kehoe Author

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Oct 22, 2021 10:47 AM in response to Thomas Kehoe

What is a "broken seal" on an SSD? That was the original error message. If I could fix that I wouldn't have to go down this rabbit hole of making a bootable external drive.

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Answer 5

Thomas Kehoe Author

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92 points

Oct 22, 2021 1:47 PM in response to Grant Bennet-Alder

OK, that explains why Apple's instructions don't result in what I want.

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Answer 6

Thomas Kehoe Author

Level 1

92 points

Oct 22, 2021 9:20 AM in response to Encryptor5000

I downloaded and installed Big Sur on the external SSD. The problem with your plan is that Migration Assistant transfers data from one computer (Mac or Windows) to another computer. It doesn't recognize an external SSD as a computer.

It's possible that your plan might work if the external SSD were bootable. My MacBook won't boot from the external SSD. I don't understand why. I'll work on figuring this out before I try Carbon Copy Cloner.

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Answer 7

Oct 21, 2021 6:31 PM in response to Thomas Kehoe

what model-year MacBook Pro?

If it has a T2 chip, you may need to change some settings in

About Startup Security Utility - Apple Support

.

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How do I copy my internal SSD to an external SSD?

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