El Capitan Boot From Usb

Summary

To create a bootable Mac drive you need any disk with Mac OS X 10.11.0 El Capitan or newer (10.12 Sierra, 10.13 High Sierra, 10.14 Mojave, 10.15 Catalina) either running as your main system, or just being installed on a drive that's connected to your Mac at the moment.

El capitan not booting from usb

How to make a bootable USB drive on Linux Mint (19.3) to allow you to install Mac OS X El Capitan on a MacBook with broken or corrupted recovery mode.

Background

HOW TO: Use DiskMaker X To Create A Bootable OS X El Capitan USB In Just A Few Clicks easiest way to create a bootable OS X El Capitan flash drive DiskMaker X (formerly Lion DiskMaker) is an application built with AppleScript that you can use with many versions of OS X to build a bootable drive from OS X installer program (the one you download. The OS of the older Mac has been corrupted and cannot boot. Yes I have downloaded El Capitan (InstallMacOSX.dmg) and renamed it to Capitan.app in the Applications folder. On the terminal, the. I read through it though but what I needed was a way to make a bootable El Capitan USB (for use in an older Mac) while on a newer Mac running Catalina. Currently, you can only create a bootable installer for macOS Big Sur, Catalina, Mojave, High Sierra, or El Capitan. If you want to go back to your previous macOS, here's how to downgrade macOS. Posted November 18, 2015. Hello, I love your bootables versions of OS X, Yosemite was perfectly installed on my FusionDrive with UEFI. But I think I have a problem with the El Capitan version. With the Yosemite bootable USB untouched, Clover shows the good FusionDrive partition ' Macintosh HD'.

Boot

I was recently given a 2011 MacBook Pro that had been “well-loved” and was therefore a mess of missing applications, ghost files and generally slow-as-hell. Since there wasn’t much worth saving I wiped it and initiated recovery mode in order to re-install OS X (El Capitan).

Having recently fixed a busted MacBook Air I had learned a bit about Recovery Mode (hold Command+R whilst pushing the Power button and release a few seconds after the machine wakes up). I tried that with this machine, and upon hitting “Reinstall MacOS X” was greeted with a prompt telling me it would take -2,148,456,222 days and 8 hours (an uncaught buffer overflow, me thinks). After about 30 seconds, a window pops up saying “Can’t download the additional components needed to install Mac OS X” and the installation gives up. The detailed error log says “Chunk validation failed, retrying” about 1000 times and eventually gives up altogether.

Further investigation suggests this may be something to do with security certificates having expired and hence the machine not being able to download the necessary files from Apple’s servers, but it seems the error can appear for all sorts of reasons. I also tried Internet Recovery (Command+Option+R) but that gave exactly the same error (and would also only have installed OS X Mountain Lion).

I then turned to attempting to make a bootable USB stick of OS X El Capitan from an image downloaded from Apple. I use Linux Mint on my main laptop and that was all I had available. Apple seem to assume everybody has a spare MacBook from which to create a bootable USB so they provide absolutely no documentation to help with this. I also couldn’t find a single guide online that worked from start to finish, so here I summarise what needs to be done.

Steps

As usual, this is all at your own risk 🙂

First you need to go to Apple’s OS Download Page and (step 4) get ahold of “InstallMacOSX.dmg” for El-Capitan. It’s a 6GB file so it might take a ‘lil while. You will also need to find a USB drive with at least 8GB capacity, and make sure it’s blank. The format doesn’t matter, because this procedure will format it correctly.

(In total you will need to use about 15-18GB of disk space by the time you’ve done all the extracting necessary, which shouldn’t be a problem for most computers but it was a challenge for my laptop with it’s 128GB SSD and dual boot Windows/Linux!)

Then you need to get a program called ‘dmg2img’

You can then extract the DMG

Now double click the .img file to mount it. In there is a InstallMaxOSX.pkg file. This requires a utility called “xar” to extract, which can be installed with these instructions (from https://www.oueta.com/linux/extract-pkg-and-mpkg-files-with-xar-on-linux/)

Then build and install with

Now you can extract the .pkg file. It will extract to the current working directory

Now, within the extracted files you will find something called InstallESD.dmg. This actually contains all the interesting boot files, but it isn’t a pristine image, so we can’t just burn it to a USB. Thankfully, a script exists to convert this DMG to a bootable usb, and it’s available here. It takes the DMG and writes everything directly to the USB in the right place.

ONE CAVEAT: When I ran this script on my InstallESD.dmg, it crashed because it didn’t recognise the checksum. I think this is because Apple updates the dmg’s anytime there is a security update for El Capitan so the checksum list isn’t updated. All I did was delete the checksum check from the script above. Essentially, just open the script and delete this section

Once I had done this, I ran the script with my USB connected (/dev/sdb for me, but CHECK YOURSELF with fdisk or similar) and after quite a while it finished copying.

I plugged the USB into the MacBook, and opened the startup menu by holding down Option whilst pushing the power button. This gave me the choice of booting from EFI, or choosing a WiFi network. Click on the EFI, and then follow the prompts to install OS X from the USB drive!

When you’re done, you may need to use Parted or a similar utility to re-format your USB as a normal drive again.

DiskMaker X (formerly Lion DiskMaker) is an application built with AppleScript that you can use with many versions of OS X to build a bootable drive from OS X installer program (the one you download from the App Store). As soon as you launch the application, it tries to find the OS X Install program with Spotlight. Then, it proposes to build a bootable install disk and make it look as nice as possible. It’s the easiest way to build an OS X Installer in a few clicks ! Then you can use the Install drive to fully re-install the OS on a freshly formated drive, or install it on your many Macs without re-downloading the full installer.

Jump over the break to learn how to use DiskMaker X…

Create El Capitan Boot Usb

1. Get an an empty flash drive with at least 8GB of storage

2. Download OS X El Capitan

3. Download DiskMaker X

El Capitan Boot From Usb

4. Double-click on the .dmg file to open it and drag-and-drop the DiskMaker X app into the Applications folder


5. Now load DIskMaker X. When you load the app, it will ask you which version of OS X do you want to make a boot disk of. You can choose Mavericks, Yosemite and of course, El Capitan. We’ll choose El Capitan

6. Now, the app will search for a copy of OS X El Capitan. Once it found your El Capitan copy, it will ask you if you want to use the copy that it found or you want to use another copy. If you downloaded it from the app store ( step 2 ), choose ‘Use this copy’

Make El Capitan Install Usb

7. Now the app will ask you about your thumb drive, and it will tell you that will be completely erased before copying OS X El Capitan onto it…

8. Now the app will format your flash drive and ask you for your admin password. Once you enter your admin password, DiskMaker X will start copying the necessary El Capitan files onto your flash drive.

Boot From Usb Mac


NOTE: this process will take a while. Be patient….

El Capitan Boot From Usb Drive

9. When you’re done, the app will tell you that the boot disk is ready, you’ll see that your flash drive has been renamed as OS X 10.11 Install Disk and it will be opened. Now all you have to do is restart your Mac and and after you here the chime sound, press the Option ( Alt ) key until you see the option to choose the flash drive to boot from.