Help with Terminal command please

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cwo...@gmail.com

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Mar 1, 2021, 3:13:19 PM3/1/21
to Sussex Mac User Group

I have got myself in a bind and cannot proceed using the external commands so I will have to use Terminal to copy the contents of an external drive called "ext1" to an internal drive called Main1.  Please can you supply the Terminal commands. 

The machine will not boot at the moment as the Main1 drive/partition contains some key information. which is not available.

An alternative would be to get the machine to boot up from the external drives/partitions - however that is beyond me at the moment

Thanks for any help

Derek Wright

Sam - MacAmbulance

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Mar 1, 2021, 4:57:32 PM3/1/21
to 'Jason Davies' via Sussex Mac User Group
Hi Derek

Was that an old email? I can’t see the thread it relates to.
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Sam Mullen

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cwo...@gmail.com

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Mar 1, 2021, 5:41:57 PM3/1/21
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No this is a genuine question - have I put it in the wrong section?ks

Thanks

Sam - MacAmbulance

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Mar 1, 2021, 6:29:39 PM3/1/21
to 'Jason Davies' via Sussex Mac User Group
If the machine won’t boot then how will you run the terminal commands to copy ext1 to Main1? There are different terminal commands which can be used to copy files from one place to another, such as : 

rsync -avz /Volumes/ext1/ /Volumes/Main1/
cp -Rvp /Volumes/ext1/* /Volumes/Main1/

Some things to consider :

If ext1 has a bootable clone of Main1, boot form ext1 by holding alt at startup.
If ext1 doesn’t have a bootable clone of Main1, copying the files won’t enable the Mac to boot from Main1.

Your best bet if probably to boot from internet recovery (alt+cmd+R at startup) > Reinstall macOS on Main1 > boot up and copy the files from ext1 to where you want them to go on Main1.

I’d need a bit more info about the current situation to come up with an exact solution though.

_

Regards
Sam Mullen

+44 (0)7747778022
in...@macambulance.com
www.macambulance.com

MacAmbulance

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MacAmbulance Ltd. is a registered company in England & Wales, registration number 8466597

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cwo...@gmail.com

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Mar 2, 2021, 9:49:33 AM3/2/21
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The bit more information......
I am moving from a 2009 Mac Pro that had 5 active spindles to an iMac
I wanted to keep the drive concept running on the new machine because that helps me to remember where all the data is located, eg text, pictures etc.
On the new machine I decided to use 4 equivalent partitions to correspond to the drives I had on the Mac Pro.
Fortunately I take nightly copies of each partition to a 4GB disk drive. using Carbon Copy Cloner.
The reason for moving to the iMac was that the Mac has died - it does not fire up. It was running Big Sur.

During my build up of the iMac I inadvertently deleted the contents of Partition 1 which is why I want to copy it from the backup drive to the main drive.   For security reasons Apple do not want users booting from external drives.

So that is why I need to copy the contents of the drive to the empty partition on the iMac.

If I could boot up from the external backup set of drives I would be OK but Apple has got very sensitive on using external drives during the boot process.

So that is where I am at and why I got here.
Thanks for your interest

Regards
Derek Wright

Sam - MacAmbulance

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Mar 3, 2021, 5:19:54 AM3/3/21
to 'Jason Davies' via Sussex Mac User Group
Current intel iMacs are capable of booting from external drives, even the new M1 Macs still boot from external if you hold down the power button at startup. What do you mean by Apple have got very sensitive on using external drives?

If you copied the files using a terminal command you probably wouldn’t end up with a bootable backup as there are lots of different commands run by CCC. Your best bet is to boot from Internet Recovery (if you can’t boot from an external drive), reinstall macOS on Partition 1 on the iMac, then use the built-in migration assistant which will run straight after macOS reinstallation, choosing the MacPro’s boot partition to migrate from.

_

Regards
Sam Mullen

+44 (0)7747778022
in...@macambulance.com
www.macambulance.com

MacAmbulance

MacAmbulance Ltd.

Providing Affordable Mac/PC Support and Web Development

MacAmbulance Ltd. is a registered company in England & Wales, registration number 8466597

This email is intended solely for the addressed recipients and may contain privileged or confidential information.

If you have received this email in error please notify the sender and delete the email immediately.

Tony Crooks

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Mar 3, 2021, 7:45:52 AM3/3/21
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I may have misunderstood but Big Sur requires APFS formatted storage to run an OS from. Carbon Copy Cloner isn’t able to copy the OS volume so wouldn’t have been saved from the Mac Pro. Sam is correct in that you would need to reinstall Big Sur via Internet Recovery and then you could either recover your user spaces/data using CCC or better but slower using the Migration Assistant.
You can download Big Sur from the App Store and install it on an external device which you can boot from. And then CCC can be used to backup data only. It will not backup any changes to the OS and Bombich has a blog post explaining all this quite clearly. The external drive is bootable - I know as I’ve done it on my M1 Mac mini (and that has additional complications at present that it is only bootable from a drive connected to a Thunderbolt port.). I posted a Tidbits article about the needs to rethink backup strategy to the group recently because of all the changes.

Sam - MacAmbulance

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Mar 3, 2021, 7:53:16 AM3/3/21
to 'Jason Davies' via Sussex Mac User Group
CCC can copy the read-only system volume, it just can’t update it on the next scheduled clone. 

If you’re only cloning the once it’s fine as CCC will ask to erase the target partition. I do this regularly when upgrading client storage.

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Regards
Sam Mullen

+44 (0)7747778022
in...@macambulance.com
www.macambulance.com

MacAmbulance

MacAmbulance Ltd.

Providing Affordable Mac/PC Support and Web Development

MacAmbulance Ltd. is a registered company in England & Wales, registration number 8466597

This email is intended solely for the addressed recipients and may contain privileged or confidential information.

If you have received this email in error please notify the sender and delete the email immediately.

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cwo...@gmail.com

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Mar 3, 2021, 12:04:12 PM3/3/21
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After another call to Apple I have now got my new computer up and running with all my data (I think)
Thank yyou for all your comments. Big Sur is quite a change from Catalina.
Thanks for your comments.
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