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iMac--boot from external SSD
- Thread starter jimiblue
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Once you plug it in, open Disk Utility and select the drive and format as APFS and use GUID Partition Table.
Then you can use a utility like Carbon Copy Cloner to clone your internal HD into the SSD, or do a clean install of macOS and start fresh.
You can boot into it by holding down Option at startup and selecting the drive.
Then you can use a utility like Carbon Copy Cloner to clone your internal HD into the SSD, or do a clean install of macOS and start fresh.
You can boot into it by holding down Option at startup and selecting the drive.
A more detailed two-part HOW_TO can be found at the OWC site:
eshop.macsales.com
Using an External Drive as Your Startup Drive: Part 1
Having problems with your internal startup drive? Perhaps you need something faster to boot from? Using an external drive as the boot device might be the solution.
eshop.macsales.com
OP:
Tell us what kind of drive you have (USB or thunderbolt). If you DON'T HAVE the SSD yet, TELL US, we can make recommendations.
Tell us which version of the OS you're using.
You want to use disk utility.
If you're using Low Sierra (10.12) or High Sierra (10.13), I'd suggest erasing the drive to Mac OS extended with journaling enabled, GUID partition format.
If you're using Mojave (10.14) or Catalina (10.15), use APFS with GUID partition format.
Then, use CarbonCopyCloner to clone the contents of the internal drive to the external drive. Note: this works IF everything you have on the internal will FIT onto the SSD. If your SSD is smaller than the internal, you'll have to "pick and choose" what you move over -- CCC can still do this for you.
Get CCC here:
www.bombich.com
CCC is FREE to download and use for 30 days.
When the clone is done, you have to go to the startup disk preference pane.
Click the lock and enter your password.
Then, click on the SSD to make it the new boot drive.
Then, REBOOT.
This is not all that difficult.
If you have the SSD, just get to work.
Tell us what kind of drive you have (USB or thunderbolt). If you DON'T HAVE the SSD yet, TELL US, we can make recommendations.
Tell us which version of the OS you're using.
You want to use disk utility.
If you're using Low Sierra (10.12) or High Sierra (10.13), I'd suggest erasing the drive to Mac OS extended with journaling enabled, GUID partition format.
If you're using Mojave (10.14) or Catalina (10.15), use APFS with GUID partition format.
Then, use CarbonCopyCloner to clone the contents of the internal drive to the external drive. Note: this works IF everything you have on the internal will FIT onto the SSD. If your SSD is smaller than the internal, you'll have to "pick and choose" what you move over -- CCC can still do this for you.
Get CCC here:
Download CCC - Bombich Software
When the clone is done, you have to go to the startup disk preference pane.
Click the lock and enter your password.
Then, click on the SSD to make it the new boot drive.
Then, REBOOT.
This is not all that difficult.
If you have the SSD, just get to work.
thanks so much for the info...I bought a Samsung T5, thunderbolt, 1tb..Running the latest Catalina..Bought a used iMac 2017 with a 1T hdd..teaching from home this year--from the get-go the machine is just really sluggish, lots of rainbow wheels opening windows, tabs, programs, and nothing heavy. my wife bought a new iMac with a ssd and it is so much faster...I'm hoping this helps, cheapest and simplest way I could find to speed up..thanks for the help, ill let ya know how it works outOP:
Tell us what kind of drive you have (USB or thunderbolt). If you DON'T HAVE the SSD yet, TELL US, we can make recommendations.
Tell us which version of the OS you're using.
You want to use disk utility.
If you're using Low Sierra (10.12) or High Sierra (10.13), I'd suggest erasing the drive to Mac OS extended with journaling enabled, GUID partition format.
If you're using Mojave (10.14) or Catalina (10.15), use APFS with GUID partition format.
Then, use CarbonCopyCloner to clone the contents of the internal drive to the external drive. Note: this works IF everything you have on the internal will FIT onto the SSD. If your SSD is smaller than the internal, you'll have to "pick and choose" what you move over -- CCC can still do this for you.
Get CCC here:
CCC is FREE to download and use for 30 days.Download CCC - Bombich Software
When the clone is done, you have to go to the startup disk preference pane.
Click the lock and enter your password.
Then, click on the SSD to make it the new boot drive.
Then, REBOOT.
This is not all that difficult.
If you have the SSD, just get to work.
I don't know how unique my experience is or what lessons to draw. My 2017 27" iMac with Fusion drive is now reporting SMART errors. So I ordered the Samsung T7 figuring I could boot from it, and use Migration Assistant to put all my stuff on it. I was unable to successfully install either Catalina or Big Sur on it, from downloaded installers or from the Restore screen. Very frustrating, sometimes it would act like the install worked, but then I'd get the Forbidden icon on startup (haven't seen that before) and no boot, or other times the Kernel Panic screen. Many attempts all failed; including one while on the line with Apple support this morning. Of course Disk Utility said it was OK. So I threw in the towel and just returned it to Best Buy. What a grim experience.
I think I may try another external SSD, but I think I may take in someplace, either an Apple store or an independent place to have them install an internal drive. Sigh.
I think I may try another external SSD, but I think I may take in someplace, either an Apple store or an independent place to have them install an internal drive. Sigh.
I have the Samsung T7 and I am able too use it this find on Big Sure with no issue what so ever
Check if you are using a T7 Touch version. T7 touch is not going well with OS installing.
Better use a non-touch T7, format it (APFS) before installing Catalina
Thanks. It wasn't touch, and I did format it APFS. Looking more and more like a bad unit. Getting a new drive today. But sure did cost me a lot of time.
Great thread! I, too, am tired of my 2017 HDD. I only have a 500 GB T7 Samsung with not enough space for SafetyNet via CCC. Originally, I was thought I was booting from the SSD, but still storing files on my original 1 TB HDD as I still want to use it. Is this not advised? Or any recommendations what I should delete from the SSD copy to make the boot-up work?
Hello! Can you please explain why T7 Touch is not going well with OS installing? I just ordered Touch version and want to do it my external boot drive on my iMac. Should I cancel my order?
I use a WD my passport 500GB SSD to boot my late 2015 21.5" iMac with 1TB hdd. I use CCC to copy system and application only. And leave all the files remain in the internal hdd. I haven't wipe clean the internal hdd yet, in case anything goes wrong i still can go back to it. Meanwhile my internal still has about 500GB space or so to store my files.
That information was old.
The T7 touch is equipped with data protection software, so out of the box you cannot partition it. Need to download Windows application to unlock before you can re-partition and format it to APFS.
Samsung Portable SSD T7 not working with … - Apple Community
So I need to unlock disk just like this guy in the link? And then everything will be fine?That information was old.
The T7 touch is equipped with data protection software, so out of the box you cannot partition it. Need to download Windows application to unlock before you can re-partition and format it to APFS.
Samsung Portable SSD T7 not working with … - Apple Community
discussions.apple.com
Then it would be a normal non-touch drive. Which is OK if you don't really care about the price difference.
Thank you very much for your explanation. My problem was that in my city stores have only touch version, I couldn't find non-touch T7, that's why I'm buying one with fingerprint, although I will not use any security features. Once again – thanks a lot!
On a 2017 (as well as 2019 and pre-2017) iMac, It's pretty much the exact same as preparing an internal drive.
1. Open Disk Utility, format the drive (use APFS if you're trying to install macOS High Sierra [10.13.x] or newer; use HFS+ if you're trying to install Sierra; I doubt a 2017 iMac can run any earlier than Sierra).
2. Either (a) boot from a bootable USB drive installer for your macOS release of choice and run the installer from there, (b) boot from Internet Recovery and run the installer from there, or (c) download your macOS release of choice and run the installer from within your HDD's OS
3. Select the SSD you formatted earlier, when asked where you want to install macOS to and then sit back and relax
4. **Optional** If you want to copy the data that lives on your HDD over so that it's on the SSD, run the Migration Assistant when prompted to and target your Internal HDD as the "other Mac".
My personal recommendation is to use a Thunderbolt 3 drive. USB 3 will still be plenty fast, but you lose 1Gbps of theoretical maximum transfer speeds between the drive and the system when compared to the internal interface that the hard drive uses. Thunderbolt 3 will allow for WAY faster transfer speeds. Though, if you're using a Thunderbolt 3 SSD that is basically a SATA drive in an enclosure, then it's kind of a waste of Thunderbolt 3 (in which case, you might as well have just gotten a USB 3 SSD). 10Gbps USB-C drives would also be a decent improvement and ought to not cost as much as a Thunderbolt 3 drive might.