Install To External SSD?

[PBG4 Dude]

For the record, I'm able to boot Mojave on a USB3 SSD.

My recipe:
1: High Sierra system on internal SSD block-cloned to external USB SSD
2: Ran "Install macOS 10.14 Beta.app" with the USB SSD as the target
3: There's no step 3

YMMV, but this worked perfectly fine on my Mid-2012 MacBook Air.

Like I said in my earlier post, it works fine on my 2012 Air. It does not work on my 2017 MacBook Pro. This problem seems to affect only the 2016-2017 machines. Found a thread in Apple’s developer forum where other people are having the same issue.

 

[Apple_Robert]

I installed Mojave on a external SSD (Crucial MX100) connected to my 2017 iMac. No problems noted with the installation process. Running well thus far, albeit slower than what I am used to with my iMac.

 

[Klheard]

I had the same issue after three hours of troubleshooting I have a solution. I unplugged the external ssd from my iMac and connected it to my MacBook Pro. I did not boot from the external SSD instead I had my MacBook do the install to the external ssd. When my MacBook finished the install and tried to boot into the external ssd I got an error. The no go sign with the slash. I plugged the external ssd back into my iMac. The iMac booted into the ssd just fine even though my MacBook wouldn’t. Weird.

 

[Jory de Kort]

I have had the same issue with a new T5 Samsung Portable SSD and the MacBookPro14,3 (15inch, 2017, Touch Bar)

Installation starts, than after 20 min it shows a stop sign and I tried pretty much every road to Rome on this one:

1. Clean install from bootable drive
2. Clean install from current OS using the installer
3. Clean install High Sierra and than upgrade

I tried HFS+ and APFS, single partition, multi partitions on disk...

But all ended with the stop sign.

For me the solution was to not use the USB-C cable that came with the drive but I used to USB-C cable from the charger.... Voila installation finished as expected and now runs like a charm. Seems that macOS is getting picky on USB-C cables

 

[PBG4 Dude]

This issue was fixed with today’s beta release.

 

[BraytonAK]

…

 

[PBG4 Dude]

Are you sure the drive is partitioned correctly? Its base partition needs to be “GUID Partition Table”. This is before formatting the drive as HFS+ or APFS.

 

[thadoggfather]

Are you sure the drive is partitioned correctly? Its base partition needs to be “GUID Partition Table”. This is before formatting the drive as HFS+ or APFS.

I can just format an external SSD to HFS+ in disk utility, then point installer for Mojave to it to install right?

Don’t need high sierra?

Internal drive is also on 10.12.6 I’d be running installer from

 

[PBG4 Dude]

I can just format an external SSD to HFS+ in disk utility, then point installer for Mojave to it to install right?

Don’t need high sierra?

Internal drive is also on 10.12.6 I’d be running installer from

It’s a full OS install image so it should fire up from Sierra.

If you format to HFS+, the install will reformat to APFS.

 

[thadoggfather]

It’s a full OS install image so it should fire up from Sierra.

If you format to HFS+, the install will reformat to APFS.

Did exactly that and it worked!

This is a fun os to play with

Thanks ! Didn’t affect my internal drive or Sierra partition either as I expected

Dang does my startech usb-c to Sata get HOT where the connectors are hooked up to the drive. Luckily the drive and the usb-c port on my laptop are cool to the touch.

 

[PBG4 Dude]

Excellent! Glad it worked out for you!