External storage won't mount at startup - only happens at login, which is too late

I managed to resolve this issue by creating the following custom plist file.

It's not that daunting.

You simply create a plist file in the folder... Macintosh HD/Library/Preferences/SystemConfiguration/ (You may need to create the SystemConfiguration folder as my machine did not have one)

Name the plist file autodiskmount.plist

If you don't know how to create a plist file you can copy one from another Library folder, rename it autodiskmount.plist and then open it with TextEdit.app

Now replace the file contents with the text below, save and restart.

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">

<plist version="1.0">

<dict>

<key>AutomountDisksWithoutUserLogin</key><true/>

</dict>

</plist>

I should add that this may not stop external drives un-mounting on logout, which they currently do.

I'm hoping this is just a bug that they will fix because it seems weird that it would be designed like that. Given the cost of storage on these devices many uses must be running external storage for data.