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Saintadi

macrumors newbie
Original poster
Oct 24, 2018
1
0
Hi
I have an iMac 2017 1TB HDD which I bought 500 GB Samsung T5 external SSD and cloned it.
it is much faster now however, the issue is I am not seeing an external drive in the default start up disk option in system preferences.
So every time I boot the computer I have to press Option to select the T5 otherwise it will go straight to the slow HDD, which I have been doing for months. I looked up online there are some people with this problem but no solution that I can find.

Any thoughts or solutions will be much appreciated.

I am running high Sierra 10.13.5

Best
 
This is by design and has been for years.

After you boot into your preferred drive, go to System Preferences/Startup Disk. You'll have to click on the padlock icon and enter your Admin password. Now select the drive you want to boot from. You're done.
 
Last edited:
Hello I just cloned my hard drive on my 21.5 late 2014 iMac (Mojave) to a T5 from Samsung (1tb) using super duper. When i reboot and hold option i can select the SSD, however once booted its amazing but once i restart it defaults back to the HDD. I looked in startup disk and it wasn't listed only the HDD was any thoughts on how to fix this?
 
So basically reformat the external SSD and redo everything using the migration assistant feature. I’m keeping the ssd external. Sorry I’m not very computer savvy lol.
 
gfbaldin wrote:
"So basically reformat the external SSD and redo everything using the migration assistant feature. I’m keeping the ssd external. Sorry I’m not very computer savvy lol."

No, Mr. Halloran has it right above.

Hmmm.... try this (in the exact order presented, print this out if you have to):
1. Power down all the way off
2. Connect the t5 (with Mojave on it)
3. Press the power on button
4. IMMEDIATELY hold down the option key and KEEP HOLDING IT DOWN until the startup manager appears
5. Select the t5 with the pointer and hit return.
6. You should now boot into Mojave (on the t5)
7. Log in and get to the finder
8. Go to the "startup disk" preference pane (system preferences)
9. Click the lock icon at the bottom and enter your password
10. Click the icon for the t5 to select it to be the boot drive
11. Close system preferences
12. Now power down again, ALL THE WAY OFF
13. Press the power on button, DON'T hold down the option key
14. Do you boot to the t5 (Mojave) now?

Try this and get back to us.
 
gfbaldin wrote:
"So basically reformat the external SSD and redo everything using the migration assistant feature. I’m keeping the ssd external. Sorry I’m not very computer savvy lol."

No, Mr. Halloran has it right above.

Hmmm.... try this (in the exact order presented, print this out if you have to):
1. Power down all the way off
2. Connect the t5 (with Mojave on it)
3. Press the power on button
4. IMMEDIATELY hold down the option key and KEEP HOLDING IT DOWN until the startup manager appears
5. Select the t5 with the pointer and hit return.
6. You should now boot into Mojave (on the t5)
7. Log in and get to the finder
8. Go to the "startup disk" preference pane (system preferences)
9. Click the lock icon at the bottom and enter your password
10. Click the icon for the t5 to select it to be the boot drive
11. Close system preferences
12. Now power down again, ALL THE WAY OFF
13. Press the power on button, DON'T hold down the option key
14. Do you boot to the t5 (Mojave) now?

Try this and get back to us.
[doublepost=1543442474][/doublepost]For some reason I don’t have anything in there but when I hold option after turning on I can see the T5 and boot and it works great. But when I restart it’s defaulting back to HDD
 

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"For some reason I don’t have anything in there but when I hold option after turning on I can see the T5 and boot and it works great. But when I restart it’s defaulting back to HDD"

Have you also done the following?

1. Boot to the recovery partition (restart, hold down "command-R"
2. Open "Startup Security Utility" (I -think- that's the name for it)
3. Choose either "medium" or "no" security (you might have to try both)
and then...
4. Choose "allow booting from external media"

???
 
Sounds like it was not made bootable. Migration Assistant may not do this,CCC and SD do.
When I erased the sad drive initially to format it. I didn’t select guid partition I selected on bootdisk option. Maybe that was it. I reformatted it’s still going I’ll keep ya posted
 
Well now I used CCC and cloned it. It showed up however when I attempt to use the drive I get an error message when trying to boot from the SSD drive “your computer restarted because of a problem” and it keeps restarting. This has turned into a nightmare!!! Lol
 
Command r does not work in High Sierra or later if there's another copy of the OS anywhere on your system. In your case, there's a copy on the HDD so Command r can't work except into the HDD if Sierra or older.

Cloning: There is no Repair partition on any cloned drive until the OS is reinstalled. If you haven't reinstalled the OS onto the external drive, now's the time to do so. This does not erase your data but it may fix the Problem. Since you can't Command r into the external, you will need to boot from a drive that has Mojave installed such as a prepared external or USB stick.

If you can boot into that external, you could download the Mojave installer and run it—after you've gone to Preferences and re-selected the external as your boot drive.

Sounds like it was not made bootable. Migration Assistant may not do this,CCC and SD do.
That's wrong in a number of ways. You can't push the OS through Migration Assistant—it only works after you've booted onto the drive. MA only pulls files and settings over.
 
Command r does not work in High Sierra or later if there's another copy of the OS anywhere on your system. In your case, there's a copy on the HDD so Command r can't work except into the HDD if Sierra or older.

Cloning: There is no Repair partition on any cloned drive until the OS is reinstalled. If you haven't reinstalled the OS onto the external drive, now's the time to do so. This does not erase your data but it may fix the Problem. Since you can't Command r into the external, you will need to boot from a drive that has Mojave installed such as a prepared external or USB stick.

If you can boot into that external, you could download the Mojave installer and run it—after you've gone to Preferences and re-selected the external as your boot drive.

That's wrong in a number of ways. You can't push the OS through Migration Assistant—it only works after you've booted onto the drive. MA only pulls files and settings over.



I’m sorry I’m new to all this. Sounded really easy to do. How do I reinstall os on ssd.
 
gfbaldin --

Let's get something straight:
What can you boot from RIGHT NOW?

Does the Mac boot from the internal drive?
If not, do you have ANY external drive you can boot from?

If not...
And if you live close to a brick-n-mortar Apple store...
... it might be time to haul the iMac in and have them make it bootable for you again.
 
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