Apple's macOS Mojave 10.14 is Upon Us! How to make a bootable USB installer

Apple just released macOS 10.14 Mojave!

As Always: BACKUP EVERYTHING and DO NOT UPGRADE YOUR SYSTEM OR APPS IN THE MIDDLE OF A PROJECT.

Mojave is brand new, and even though it is stable a lot of plug-ins, apps and add-ons shenanigans are not yet 100% compatible. So BEWARE and TEST your stuff before diving-in. I have a Mule machine that I load with new installs for my own tests, and I'm very thorough and prudent. I won't upgrade my main system before some time.

Apple conveniently explains how to make a bootable USB flash drive installer with Mojave  in this support page, using the 'createinstallmedia' command in Terminal.

But first, download Mojave from the Apple Store, and Quit the installation when the installer opens.

Mojave install file is 5.7GB according to Apple.

Check that your computer and graphic card are on the list. 

For MacPro owners like myself, the upgraded graphic card must be Metal capable:
macOS Mojave requires a graphics card that supports Metal, an Apple technology that lets the system and apps efficiently tap into the capabilities of today’s graphics processors (GPUs). The graphics cards offered by Apple in Mac Pro (Mid 2010) and Mac Pro (Mid 2012) don't have GPUs that support Metal, so these systems require upgraded graphics cards in order to install macOS Mojave.

And for some reason you must be on High Sierra before the upgrade:
Before you upgrade to macOS Mojave on these Mac Pro models, you need to update to macOS High Sierra 10.13.6 and then make sure that your graphics card is compatible. You also need to turn off FileVault. First, use the Mac App Store to update your operating system to macOS High Sierra 10.13.6. Don't upgrade your Mac Pro (Mid 2010) or Mac Pro (Mid 2012) to macOS Mojave directly from macOS versions prior to 10.13.6.

I will soon install Mojave on my second MacPro machine and will report any hiccups with my usual apps in future posts. Let me know how it performs on your system in the comments below. Cheers!

How to create a bootable High Sierra Flash USB installer

Download High Sierra from the AppStore. When prompted to install, CANCEL the installation: Quit High Sierra Installer.

In your Application folder you will see a "Install macOS High Sierra.app" that's in my case 5.18GB in size.

Get a Flash USB drive that's 8GB or more. Mount it on your Desktop. Rename it "MyVolume" (or change the name of the volume in the command below to reflect the name of your device.)

Open Terminal, type:

sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ macOS\ High\ Sierra.app

It will ask for your password and if you wish to erase your "MyVolume" device.

Let it rip! It will takes several minutes to complete.

Enjoy your new installer!

Apple support page for making USB installers with various OSes:

https://support.apple.com/en-us/HT201372

Drive performances are not made equal - a few speed test comparisons

Some are abysmal! Like this Patriot USB 2.0 32GB flash drive:

Seriously flawed!

Compared to this no name USB 2.0 16GB flash drive:

Useless for most tasks.

Obviously pale in comparison to this (meh!) WD My Passport for Mac USB 3.0 1TB portable hard drive:

That's acceptable for HD work, certainly not fast.

What's a bit better is this WD Red 2TB 3.5 bare hard drive in a USB 3.0 (or eSata dock, or on the internal Sata bus):

Acceptable, OK fast for most HD work.

This G-Drive 4TB USB 3.0 beats it by another a small margin:

Acceptable, OK fast for most HD work.

The old CalDigit 5 hard drives Raid0 4.7TB via eSata is still faster though:

OK fast for most things HD (but NOISY! as in LOUD FAN NOISE)