How do I migrate from internal to external SSD on same iMac?

AppleIIme Said:

"How do I migrate from internal to external SSD on same iMac?: I would like to use Migration Assistant. The reason is, on the advice of other users here, I want to do a migration excluding Applications and Settings, to help clean up the system. Cloner apps would clone everything, and I have to pay for them. Is there any way to move to bootable external SSD using Migration Assistant whilst installing a clean copy of macOS but excluding apps?"

-------

See my Post:

• I had a Similar Problem: Your computer has detected a potential problem Click “Send to Apple” to submit a report to Apple - Apple Community.
• How I Reinstalled it: I Ended up reinstalling this anew: (backing up my hard drive > formatting > performed clean install > migrating with TMB > and getting licenses reactivated from Developer).
• As of this reply, I am still trying to figure out the error message pertaining to the post, as to where it all came from.

So, you'd reinstall the macOS anew:

You'd backup your Mac, reinstall the macOS anew, and then Migrate items back.

1. Create: a Time Machine Backup using an external Hard Drive
2. Install: from a USB Installer created for macOS 10.14 Mojave
3. Migrate: items from your TMB
4. Download then Install: the applications, getting the programs back from the Developers.***

***Note: If Applications are not migrated, yo may need to get licenses reactivated. To get this complete, contact the Developer). A Restore did not fix this, nor did a TMB Recovery, 

It is not that hard to perform a clean install and migrate your account.

As discussed elsewhere, this avoids bringing back all the stuff accumulated over the years.

Below you find instructions on how to make a clean install on your external and migrate the stuff.

Even though you are not erasing the internal drive, you should have a backup before proceeding.

-------

• Download the full installer from the App Store. If the installer starts automatically, quit it.

• Create an installer drive on a thumb drive, following the instructions here:

How to create a bootable installer for macOS - Apple Supportsupport.apple.com › en-us

• On recent macs, you may need to authorize booting from an external drive, which may be disabled by default. You do this in "Boot Security Utility".

Information about this is available in this support document:

https://support.apple.com/en-us/HT208198

---- do not proceed further without a backup!!!! ---- 

• Restart your mac holding the Option key, and select that installer disk to boot your mac

• Use Disk Utility to reformat your destination drive as APFS. Erase the full drive, not just the volumes inside it

• Quit Disk Utility and start the installer. Select the drive where you want to install and proceed

• When asked, choose to migrate content from "another mac, time machine or drive". You can select your internal drive as the source

IMPORTANT: elect to migrate ONLY user accounts; NOT applications, settings or other files

carbon copy cloner is free for the first 30 days of use.

The reason is, on the advice of other users here, I want to do a

migration excluding Applications and Settings, to help clean up the

system.

Who are they? seems like the kind of advice you'd get on a windows system.

You have two level 10 users and me as a level 6 user saying to use a cloning utility. It's going to be a PITA to get all your old settings configured.

You can be on your own. You can download your current version of macos from the app store. You can install it on the external drive. you can use migration assistant. to copy over what you want.

R

Just to add to what Luis said, I use TM for backup history and CCC for immediate backup, and I also use Migration Assistant. During the installation process you have the option to migrate. I migrate just the user from CCC because it’s much quicker than TM. Just because CCC and SuperDuper! are clones you don’t have the migrate the whole clone.

Good point, Tom. I agree completely.

I do the same thing (well, I use SuperDuper! because I have bought it a long time ago and, just like FCP, have had free updates for years; of, CCC is fine, too).

On a sidenote, if you don't mind my asking: how is the speed of doing these backups?

I always find that backups with SuperDuper! or CCC are quite slow. [I tested the trial of CCC because of this, but found it only marginally faster than SuperDuper!]

Even if both drives, source and destination, are SSD, and using an incremental backup, where the two drives have mostly the same content (say 95% the same files), it takes a long time. The "effective copy speed" does not even come close to what the drives are capable of.

SD! and CCC are very similar. The first backup is slow, but nothing compared to TM. Incremental clones after that are very quick because it only copies altered files The restore/migrate from CCC is much, much faster than TM. I’m guessing because of TM’s history the files are very scattered and have to be cherry picked from the directory. CCC seems more reliable on migrate. I’ve had failures with TM during the process.

Thanks. Yes, I understand the principle, and I agree.

My question was not about migrating, but the speed of doing those incremental backups in SuperDuper! and CCC.

My problem is that those incremental clones still take a looong time, and I have been unable to figure out what is wrong.

A full backup of, say, a 500GB drive with 400GB worth of files takes a long time. Fine.

The expectation is that if only 10GB worth of files changed since the last clone, it should go very fast.

It does go somewhat faster than the first backup, but it still takes an enormity of time (and that is between two fast SSD).

So I just did an incremental backup on CCC from the internal SSD of the MBP to an external 500 GB SSD. It was just over 19 GB and took 12 minutes 25. Time Machine was also running at the same time, which must have slowed it down somewhat. Obviously that's not as fast as just copying that amount of data, but then the application is also pawing through hundreds of thousands of files on the system drive.

According to CCC these clones will no longer be bootable drives in the next OS. You'll only be able to clone the data partition. You can of course install an OS on it, but the OS won't be part of the clone. You'd have to boot into and update the OS manually.

Use a cloning app such as SuperDuper! or Carbon Copy Cloner.

Carbon Copy Cloner...

http://www.bombich.com/software/ccc.html

12 minutes seems fair. In my case something like that would take about 30 minutes.

Thanks for the heads up about the next OS.