Summary
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
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).
As usual, Apple no longer supply a bootable USB Flash Drive with latest OS X releases - including the new OS X 10.11 El Capitan. Using this tutorial you will.
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.
As has been the case for the last few releases of OS X, the easiest method to make a USB install drive is with the free program, Diskmaker X. It’s been updated today to support El Capitan. USB Disk formatting will start now followed by the copying of files required to create bootable os x el capitan usb drive. It will take 5 to 10 minutes maximum and the Bootable USB Disk of OS X El Capitan will be ready for use. Sep 30, 2015 The app will offer to make installers for OS X 10.9, 10.10, and 10.11, and it should run on OS X versions all the way back to 10.7—support for 10.6 was dropped in the most recent release.
Make Os X El Capitan Bootable Usb Windows 7
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
Create Os X El Capitan Bootable Usb From 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.
Whenever new OS X release comes to Mac users, it is important to create a Bootable USB as a backup option to clean install. Most of the time upgrade works well, but there are chances your battery performance go poor or OS X corrupt due to apps installed on the computer. That is when we need to perform Clean Installation of OS X as the final troubleshooting method.
Download OS X El Capitan only from Mac App Store which is available right now. Great war realism mod. Simply launch App Store on your mac computer and you will see El Capitan already featured with free download button.
OS X El Capitan featured with tons of new features and improvements to existing features. I have installed it on my iMac and Macbook Pro, and so far it is great. As i mostly use my macbook pro at desk, didn’t notice any battery performance problems. There are reports from Macbook Pro and Macbook Air users who have upgraded to El Capitan regarding battery issues.
Eplan software full version with crack download. Another important step to do after downloading the OS X El Capitan is taking backup of the installation file. By default the location of the file set to /Applications folder and the file automatically deleted after completing the OS X upgrade. So it is very important for you to take a backup of the file named “Install OS X El Capitan” from “Applications” folder to create bootable USB or use it later.
Go to Applications folder by opening Finder once the download completed and OS X El Capitan installation wizard pop up comes on your desktop screen.
At this point, copy the file “Install OS X El Capitan” and paste it any folder on your hard disk drive. Now you have the copy of latest OS X released by Apple and you can use it whenever you want and share it with your friends saving 6 gigabytes of bandwidth for them.
Create OS X El Capitan Bootable USB
We are now ready to create the bootable usb disk drive of OS X El Capitan. All you have do is, follow the couple of steps suggested here and you are ready to install El Capitan on any mac computers.
Step 1: Connect USB Disk Drive to your mac computer and Open “Disk Utility” by typing it on Spotlight (CMD + Space Bar) or by going to “Applications – Utilities – Disk Utility”.
Step 2: Select the USB Drive from the list and on the Right side, select “Erase” tab and rename the USB drive as “Untitled” and click on Erase to perform the operation.
Step 3: Now the USB Drive is ready for OS X El Capitan installation. Make sure the copy of “Install OS X El Capitan” is there on /Applications folder.
Step 4: Launch “Terminal” and copy, paste the following command in Terminal then press Enter.
Step 5: Terminal will prompt for Root password, enter the root password and press enter. USB Disk formatting will start now followed by the copying of files required to create bootable os x el capitan usb drive.
Mac Bootable Usb Drive
It will take 5 to 10 minutes maximum and the Bootable USB Disk of OS X El Capitan will be ready for use.
How To Make Os X El Capitan Bootable Usb
If you don’t want to follow these steps and looking for an app to automate all these tasks and get the USB ready with OS X El Capitan then consider using, DiskMaker X which is compatible with OS X El Capitan as well. Download DiskMaker X 5 which comes around 7 MB and create the bootable usb drive easily.
Make Os X El Capitan Bootable Usb On Windows
Thanks for reading, and feel free comment below if you have any queries. Have a wonderful day, and don’t forget to share this post with your friends and followers across Twitter, Facebook and Google+.