Replacing SATA disk with ssd - no bootable media

[GoggeN67]

Want to replace an internal SATA disk with an external SSD on an iMac. Was told it was "soo easy"
Got warning, "no bootable media found".

Found that Startdisk has no ink, guess that is why I got error message.
I guess I have to link to the Start disk, not sure how to fix it.

Happy for all help!

 

[Imac Sam]

Yes, you have to format it properly. Use some cloning or imaging software to copy your old drive to the new one. Or use the recovery process to do a fresh install on the new drive.

I have an internal ssd in my imac, but I use Carbon Copy Pro to clone it to an external drive on occasion as an extra backup rather than just always rely on time machine.

 

[Fishrrman]

1. You will need either CarbonCopyCloner or SuperDuper
Both are FREE to download and use for 30 days

2. BEFORE you clone, you must format the external SSD using disk utility.
Connect it to the Mac.
Open disk utility.
IMPORTANT STEP: check to see if there is a "view" menu.
IF there IS, CHOOSE "show all devices".
(if there isn't a view menu, skip to next step)

3. Look at "the list on the left" and identify the physical external SSD.
Click on it and then click erase.
You didn't tell us WHICH VERSION of the OS you're using.
If it's Mojave and later, choose "APFS, GUID partition format".
If it's High Sierra or earlier, choose "Mac OS extended with journaling enabled, GUID partition format"

4. When the erase is done, quit disk utility and open CCC or SD.
I would accept all the defaults.
Be sure you select the internal drive as "the source", and the external SSD as "the target".

6. The clone will take a while, be patient.

7. When done, quit CCC or SD.
IMPORTANT:
Open the startup disk preference pane (system preferences).
Click the lock and click on the SSD to designate it to be the boot drive.

8. Close system preferences and reboot.

9. Is this any better?

 

[Earl Urley]

Thank goodness the PCIe slot in post 2013 27-inch iMacs doesn't require a thermal sensor cable..

It sucks that it's PCIe 2.0 x 2 channels though.. in real world throughput that's like maybe 700-800 MB/sec, but at least it beats SATA 3 speeds.

 

[GoggeN67]

1. You will need either CarbonCopyCloner or SuperDuper
Both are FREE to download and use for 30 days

2. BEFORE you clone, you must format the external SSD using disk utility.
Connect it to the Mac.
Open disk utility.
IMPORTANT STEP: check to see if there is a "view" menu.
IF there IS, CHOOSE "show all devices".
(if there isn't a view menu, skip to next step)

3. Look at "the list on the left" and identify the physical external SSD.
Click on it and then click erase.
You didn't tell us WHICH VERSION of the OS you're using.
If it's Mojave and later, choose "APFS, GUID partition format".
If it's High Sierra or earlier, choose "Mac OS extended with journaling enabled, GUID partition format"

4. When the erase is done, quit disk utility and open CCC or SD.
I would accept all the defaults.
Be sure you select the internal drive as "the source", and the external SSD as "the target".

6. The clone will take a while, be patient.

7. When done, quit CCC or SD.
IMPORTANT:
Open the startup disk preference pane (system preferences).
Click the lock and click on the SSD to designate it to be the boot drive.

8. Close system preferences and reboot.

9. Is this any better?

Thank you for very detailed information. I am a bit handicapped because the instructions seller prepared for me is is in best case not very accurate. Instructions did ao not mention a word about choosing start disk. This process did also play games with the Firewall. So I restarted without setting the start disk. Yes, it went very wrong! Unfortunately i got sellers info first so the damage was done! I had to complete a project report. So important. Had to buy a new used iMac to complete the task.

Bottom line is that I will follow your instructions very, very carefully next time!