Correct/easiest method to shift iMac to external SSD?

Schtibbie

macrumors 6502
Original poster
Jan 13, 2007
303
2
I just ordered an external USB SSD for my OMG so slow late 2013 21.5" iMac with 5400rpm drive inside (which i swear must be running at *5* rpm). But: i'm wondering about a couple of options for transferring the "soul" of this computer to that drive for bootability. I don't want the internal 5400rpm to be for *anything* really.

I have a backup (time machine, Mojave) on an external 5400rpm drive which is socked away at my office but i can drive there this weekend and grab it if i need. If I got that route, I just need to restore the whole system from that time machine backup onto the new SSD, right? And then boot to that SSD?

Is there an option where I just plug the SSD in and (somehow?) make Mojave/time-machine back ITSELF up to the SSD directly and then I can boot from there? Or would that not result in a bootable drive?

Ideally I don't buy/install and 3rd party stuff to do this...
 

wardie

macrumors 6502
Aug 18, 2008
346
106
Easiest route is use Carbon Copy Cloner or SuperDuper to clone your active boot drive to the new drive. Then just restart from that drive and off you go. Would be a good idea to refresh your Time Machine backup first just in case. I think CCC if free to use for a few days so you can do this. The other advantage of this is it will specifically clone your recovery partition also.

Ideally... you can just use disk utility to do this too, but not sure about the recovery partition. You may be able to do this afterwards though just with disk utility too.
 

Fishrrman

macrumors P6
Feb 20, 2009
17,392
5,625
You have made the right decision by deciding to "go external" using a USB3 SSD.

I've been booting and running my 2012 Mac Mini this way since the day I took it out of the box in January 2013. I'm boasting for certain, but I doubt many users in this forum have as much experience as I do in operating a Mac this way.

If you follow my instructions, I guarantee a success rate of 98% or better.

You didn't tell us WHAT SIZE the new SSD will be, and WHAT SIZE your internal drive is (and how much of that space is currently "used up").
That's important information.

Also:
- What OS are you using?

One of your premises above is WRONG:
You want to put the OS, apps, and your "basic accounts" on the SSD.
You want the SSD to remain "lean and clean" so it will perform at its best.

However:
You DO want to leave certain "large libraries" on the internal HDD.
These libraries do not "need speed" and they will continue to work fine there.

These large libraries are:
- Movies
- Music
- Pictures
- Documents (depends on how much stuff you keep in there)

Once you have the SSD "in your hands", here's what to do next:

Connect it to the Mac. Open Disk Utility and ERASE it (format it).
If your internal drive is running Mojave, you should set the partition map to GUID (first) and then choose APFS.
If your internal drive is running High Sierra or something earlier, I recommend that you set the partition map to GUID but use Mac OS Extended with journaling enabled.

OK, did Disk Utility do the job? The drive should format and then mount on your desktop.
Next, give the drive a name that will be meaningful to you.

Now, go here:
http://www.bombich.com/download.html
... and download the version of CarbonCopyCloner that is appropriate for the OS that you're using.
CCC is FREE to download and it's FREE to use for 30 days. "My method" will cost you nothing.

Now, open CCC, accept the trial, etc.
Accept all of CCC's defaults for now.

Now you have to set up CCC.
Your source drive (the internal drive) goes "on the left".
Your target drive (the SSD) goes to the "center spot". (to the right of the source)

DON'T click clone yet.
See in the center-left the popup that says "all files"?
Click it and choose "some files".

Now it's going to present you with a long list of folders/files with checkmarks.
The default is that ALL are "checked" (meaning all will be copied).
You need to change this, but selectively and carefully.

OK, go down to the Users folder and click the disclosure arrow so that you can see more.
Now, locate your own home folder and do the same.

Next, you want to UNCHECK these folders:
Documents
Movies
Music
Pictures

Leave everything else checked.

Now, click the "clone" button on the lower right and let CCC do its thing.

IMPORTANT:
CCC may ask if you wish to clone over the recovery partition as well.
YES, you want to do this.

The end result:
Your internal drive will be "cloned over" to the SSD, with THE EXCEPTION OF those large libraries that you unchecked.

Again, this depends on just how much stuff is "in" those libraries.
If (for example) you don't keep a lot of files in the Documents folder, and its size is small, then by all means "clone that over" too.
It's up to you to ascertain what needs to be done here.

OK, when the clone is done:
Quit CCC.
Power down the Mac -- ALL THE WAY OFF.
Next, press the power-on button, and IMMEDIATELY hold down the option key and KEEP HOLDING IT DOWN until the startup manager appears.
Select the SSD with the pointer and hit return.

NOW -- the moment of truth.
Do you get "a good boot"?
If you do, log in and get to the finder.
Take a good "look around".
Try a few apps.
Do things look ok?

If so, one more thing to do:
Open the startup disk preference pane.
Click the lock icon and enter your password.
Click the icon for the SSD, then close system preferences.

Time for the final test:
Power down again, ALL THE WAY OFF.
Press the power button and let the the Mac boot up (NO option key this time).
Does it boot from the SSD?

If so -- YOU'RE DONE!

PRINT OUT these instructions and read through them a few times.
Looks like work, well... it is... but just follow along, and you'll do fine!
 

Schtibbie

macrumors 6502
Original poster
Jan 13, 2007
303
2
Ah man I was hoping to avoid using 3rd party software but I will if needed. Also: I am setting up a 500 gig SSD and my entire terabyte internal slow hard drive has about 220 gigs of data on it (20 of which is gonna get nuked anyway before I do this). So I see no point only putting the OS and apps on the SSD. I am tired of both the photos app (lots of photos) and iTunes (lots of songs) taking forever to navigate and load. So I figured I would migrate the entire disk! Anyway, this is a stop-gap until there’s a new iMac available in... another year?
 

CoastalOR

macrumors 68020
Jan 19, 2015
2,486
907
Oregon, USA
Ah man I was hoping to avoid using 3rd party software but I will if needed. Also: I am setting up a 500 gig SSD and my entire terabyte internal slow hard drive has about 220 gigs of data on it (20 of which is gonna get nuked anyway before I do this). So I see no point only putting the OS and apps on the SSD. I am tired of both the photos app (lots of photos) and iTunes (lots of songs) taking forever to navigate and load. So I figured I would migrate the entire disk! Anyway, this is a stop-gap until there’s a new iMac available in... another year?
You don't have to use 3rd party software, but it is a little faster and easier.

A way to do it with just Apple software:
1. Make a fresh Time Machine (TM) backup of your current internal.
2. Connect your new SSD externally and format it with Disk Utility (Mac OS Extended (journaled) or APFS).
3. Get the Mojave full installer from the App Store or use a Mojave USB Installer (if you have it). Launch the Mojave installer and point it to your external SSD. Note: The Mojave will automatically launch if newly downloaded from the App Store.
4. Connect your TM backup when the installer asks if you want to migrate data. Let the installer continue to do it's thing.
5. After the installer is done, be patient, then boot from the new SSD with a Restart and holding the Option key.
6. Set the Startup Disk preference pane to the new SSD.
 

Fishrrman

macrumors P6
Feb 20, 2009
17,392
5,625
OP wrote:
"Ah man I was hoping to avoid using 3rd party software but I will if needed. Also: I am setting up a 500 gig SSD and my entire terabyte internal slow hard drive has about 220 gigs of data on it (20 of which is gonna get nuked anyway before I do this)."

Give CCC a try.
Once you've used it, you're going to come back here and say, "I never could have believed it would be this easy!"

Also (Important):
If your internal drive has 220gb of data, and the new SSD is 500gb, FORGET what I wrote about "checking and unchecking" stuff using CCC.

Do it this way:
1. Open CCC
2. Put the source (internal) on the left
3. Put the target (SSD) in the middle
4. Click the clone button -- you're going to clone EVERYTHING.
5. If CCC asks if you wish to create/clone the recovery partition, YES, DO THIS.
6. Sit back and let CCC do its thing (it will take a little while, remember, it's 220gb!)

That's all you need to do about that.

You still need to go through the steps at the end regarding setting up the startup disk pref pane.
 
Last edited:

Schtibbie

macrumors 6502
Original poster
Jan 13, 2007
303
2
OP update here, but there's a (small?) problem. First the good news: I got a 500GB Sandisk external USB 3.x SSD, formatted as APFS, installed Mojave fresh from my recovery partition (which then successfully restored all my apps and docs from my other external drive Time Machine backup!). Computer SCREAMS with speed now!

But: This 8 gigabyte ram computer (only) now refuses to ever swap to disk. You'd think that'd be perfect - why would you want to bother your new SSD with "vm swap" stuff, but this is my only disk now (the internal 5400 was *terrible* in swap situations, so it's not an option). Activity Monitor shows 0 bytes of swap no matter how high the memory pressure gets. Most of the time, this is fine. But as an experiment I opened a ton of applications until used RAM hit 7.9 gigs out of 8. And then the whole computer just jammed to a halt. I've seen articles about this on the web from prior OS versions but ... I guess they haven't fixed this for Mojave?
 

Schtibbie

macrumors 6502
Original poster
Jan 13, 2007
303
2
Quick question. Did you follow the fisho's instruction setting up the SSD as boot disk in System Preferences> Startup Disk? You do this by highlighting it (single click).
Yeah, it actually set up as boot disk when I was installing Mojave to it. And it boots straight into the SSD just fine without me having to select it. And it is in fact selected on that system preferences pane too. The only problem is that VM swap simply doesn’t work on external boot drives. I’m apparently not the only one who has noticed this but i’d Hoped they’d fixed it by now.

Anyway, it’s fine unless you run yourself out of RAM..
 

Fishrrman

macrumors P6
Feb 20, 2009
17,392
5,625
OP:

I see that you're on a 21" iMac -- so you can't easily add RAM.

In that case, I suggest you start exercising some "self-discipline":
- Quit apps you're not using.
- Close browser windows and tabs you won't be looking at for a while.

Just get comfortable doing these two items, and things will run better!
 

svish

macrumors newbie
Nov 25, 2017
8
8
You have made the right decision by deciding to "go external" using a USB3 SSD.

I've been booting and running my 2012 Mac Mini this way since the day I took it out of the box in January 2013. I'm boasting for certain, but I doubt many users in this forum have as much experience as I do in operating a Mac this way.

If you follow my instructions, I guarantee a success rate of 98% or better.

You didn't tell us WHAT SIZE the new SSD will be, and WHAT SIZE your internal drive is (and how much of that space is currently "used up").
That's important information.

Also:
- What OS are you using?

One of your premises above is WRONG:
You want to put the OS, apps, and your "basic accounts" on the SSD.
You want the SSD to remain "lean and clean" so it will perform at its best.

However:
You DO want to leave certain "large libraries" on the internal HDD.
These libraries do not "need speed" and they will continue to work fine there.

These large libraries are:
- Movies
- Music
- Pictures
- Documents (depends on how much stuff you keep in there)

Once you have the SSD "in your hands", here's what to do next:

Connect it to the Mac. Open Disk Utility and ERASE it (format it).
If your internal drive is running Mojave, you should set the partition map to GUID (first) and then choose APFS.
If your internal drive is running High Sierra or something earlier, I recommend that you set the partition map to GUID but use Mac OS Extended with journaling enabled.

OK, did Disk Utility do the job? The drive should format and then mount on your desktop.
Next, give the drive a name that will be meaningful to you.

Now, go here:
http://www.bombich.com/download.html
... and download the version of CarbonCopyCloner that is appropriate for the OS that you're using.
CCC is FREE to download and it's FREE to use for 30 days. "My method" will cost you nothing.

Now, open CCC, accept the trial, etc.
Accept all of CCC's defaults for now.

Now you have to set up CCC.
Your source drive (the internal drive) goes "on the left".
Your target drive (the SSD) goes to the "center spot". (to the right of the source)

DON'T click clone yet.
See in the center-left the popup that says "all files"?
Click it and choose "some files".

Now it's going to present you with a long list of folders/files with checkmarks.
The default is that ALL are "checked" (meaning all will be copied).
You need to change this, but selectively and carefully.

OK, go down to the Users folder and click the disclosure arrow so that you can see more.
Now, locate your own home folder and do the same.

Next, you want to UNCHECK these folders:
Documents
Movies
Music
Pictures

Leave everything else checked.

Now, click the "clone" button on the lower right and let CCC do its thing.

IMPORTANT:
CCC may ask if you wish to clone over the recovery partition as well.
YES, you want to do this.

The end result:
Your internal drive will be "cloned over" to the SSD, with THE EXCEPTION OF those large libraries that you unchecked.

Again, this depends on just how much stuff is "in" those libraries.
If (for example) you don't keep a lot of files in the Documents folder, and its size is small, then by all means "clone that over" too.
It's up to you to ascertain what needs to be done here.

OK, when the clone is done:
Quit CCC.
Power down the Mac -- ALL THE WAY OFF.
Next, press the power-on button, and IMMEDIATELY hold down the option key and KEEP HOLDING IT DOWN until the startup manager appears.
Select the SSD with the pointer and hit return.

NOW -- the moment of truth.
Do you get "a good boot"?
If you do, log in and get to the finder.
Take a good "look around".
Try a few apps.
Do things look ok?

If so, one more thing to do:
Open the startup disk preference pane.
Click the lock icon and enter your password.
Click the icon for the SSD, then close system preferences.

Time for the final test:
Power down again, ALL THE WAY OFF.
Press the power button and let the the Mac boot up (NO option key this time).
Does it boot from the SSD?

If so -- YOU'RE DONE!

PRINT OUT these instructions and read through them a few times.
Looks like work, well... it is... but just follow along, and you'll do fine!

I used your instructions to clone my iMac 27" with Fusion Drive to external SSD(Samsung T5). I now boot my iMac from this external drive. Very detailed instructions. Thank you very much for sharing the steps which made the process very simple.