Install To External SSD?

Could it maybe be APFS issue? Not sure if Mojave is that only but possibly you need to format the external SSD as APFS rather than HFS + /MacOS Extended Journaled?

Just guessing as I'm not sure if you can even format external drives as that but worth a go if so!

 

Today I installed Mojave on an external SSD sitting in an OWC USB3 housing and it worked fine. The drive was formatted to HFS+ but was reformatted as APFS during install. Thats with an iMac i7 Late 2012. How is your SSD connected to the Mac? Does the drive get enough power?

 

Wow, sorry to hear that. I am running out of ideas I am afraid.

 

https://www.imore.com/how-download-macos-1014-beta

Maybe answer here?

 

So Mojave doesn't ask you if you want to re-format to APFS ?

If so, bad news for HFS+ which although old .. works and is reliable. APFS is new and problomatic at least in Hi Sierra.

 

Check your USB-C to USB-C cable. I had the same problem after installing MacOS 10.14 and noticed that my original Samsung SSD T3 cable was broken. Tried another and now I am typing this in Safari 12.0 on Mojave installed on an external drive.

 

I am having the exact same issue as PBG4 Dude, I'm also getting that circle and slash icon when booting Mojave from an external SSD. I'm also on a 2017 MacBook Pro. From reading this thread, my guess is it has to do something with USB-C type MacBooks. I tried booting while holding down Cmd + V to see what's going wrong. There I'm getting an
USBHostDevice::setConfigurationGated: compliance violation: failed to enable remote wake
error. Not sure what it means, but I guess we'll have to wait for the next beta and hope they fixed it there.

 

I get the same error on a 13" Mid 2014 MacBook Pro. It's a simple USB 3.0 flash drive: https://www.sandisk.com/home/usb-flash/ultra-fit-usb

EDIT: It's the drive. Try a different drive. I tried it on another external HDD partitioned in APFS and it works just fine. I've had issues with the Sandisk flash drive even when booting Ubuntu..

 

do you have a external mouse connected to your MBP

 

macOS hasn't been playing nicely with some external enclosures. It might be that the drive didn't get blessed during install. Please report it as a bug.

 

I have an external SSD connected to my MBPr (mid 2012). I installed Mojave on it without any problems. Prior to the install, the SSD was used for the High Sierra beta testing. Last macOS install before the Mojave installation was the first beta of 10.13.6. The SSD was already formatted in APFS. One thing I did notice, after the first boot into the installation process, the screen was blank for nearly 10 minutes. The SSD is connected to the MBP via USB 3.0 cable.

 

that's good to know! I'll give it a try today.

 

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.

 

I was wondering if anybody got Mojave to run on an external drive with a USB-C type MacBook (i.e. a 2015 or newer MacBook, or a 2016 or newer MacBook Pro)?

 

I have a Mac mini with a USB 3 dock/SSD that ran High Serra and I just updated/installed Mojave over it. Didn't think anything about it until I saw this tread but it worked fine for me.

EDIT: Was HFS+ on High Serra and was reformatted to APFS with Mojave.

 

Works fine for me, too. Installed it on the very first day beta 1 hit, on an external Crucial 128GB SSD in a USB 3 enclosure. Drive was formatted as HFS+, and was reformatted to APFS during installation.