[How To] Update OSX USB Installer (especially for Yosemite & El Capitan)

[arsradu]

Hey guys!

 

Have you ever wondered if you can update the OS on the USB installer you were using a while ago?

 

Let's say you got a USB installer of El Capitan PB1 and you want to update it to PB5 or later, so that, if something bad happens to your system and you need to reinstall, you don't also need to reapply all the updates once the system is up and running again. But there is no separate installer for that. Only delta updates.

 

So, can you do that? The answer is a definitive YES, and here is how.

 

 

Prerequisites:

 

1. An already made and fully working USB installer (duh).

2. The delta or combo updates (usually coming as pkgs) that you're planning to install. You can Google for those.

 

 

The how to:

 

First of all, make sure you got all the updates in place.

 

Before you start updating, you need to make sure the packages you're installing are distribution-style packages, and not component packages.

Not sure how to check if a package is already distribution or not, but I don't think the following command will do any harm to it if it already is.

 

Otherwise you might get something like this:

Failed to open OS X Installer.

The path (null) appears to be missing or damaged.

 

 

So, to do that, you need to open up a Terminal window, navigate to the folder containing the package(s) or specify the direct path to it, and do:

productbuild --package /path/to/component.pkg /path/to/distribution.pkg

The names have to be different between the source and the output. Don't write onto the same file! It won't work.

 

This change concerns OS X El Capitan users but seems that it also affects Yosemite users. For older OS X versions, installing the update and selecting the USB drive as destination, might be enough.

 

Also, if you've got more than one update to apply, you will need to do this for each pkg individually.

 

Note: if you're planning on installing multiple Delta updates, make sure you do it in the specific order they arrived in. 

For example: to get from PB1 to PB5, you need to install PB2, PB3, PB4, PB5, without skipping any of them.

This flow most likely doesn't apply to Combo updates.

 

After that, you can go ahead and simply double click to run the installer.

 

Select your USB drive as destination.

 

Wait for the installation to complete and voila! You've got yourself an up-to-date USB installer of your favorite version of OSX.

 

Enjoy!