#Create bootable usb on mac how to
#Create bootable usb on mac mac os
#Create bootable usb on mac install
#Create bootable usb on mac update

Essentially, just open the script and delete this section echo ' # verifying installer image checksum' All I did was delete the checksum check from the script above.

#Create bootable usb on mac update

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. ONE CAVEAT: When I ran this script on my InstallESD.dmg, it crashed because it didn’t recognise the checksum. It takes the DMG and writes everything directly to the USB in the right place. Thankfully, a script exists to convert this DMG to a bootable usb, and it’s available here.

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. Now, within the extracted files you will find something called InstallESD.dmg. It will extract to the current working directory xar -xvf InstallMacOSX.pkg

#Create bootable usb on mac install

This requires a utility called “xar” to extract, which can be installed with these instructions (from ) sudo apt-get install build-essential libxml2-dev libssl1.0-dev zlib1g-dev You can then extract the DMG sudo dmg2img InstallMacOSX.dmg InstallMacOSX.img Then you need to get a program called ‘dmg2img’ sudo apt-get install dmg2img (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!) The format doesn’t matter, because this procedure will format it correctly. You will also need to find a USB drive with at least 8GB capacity, and make sure it’s blank. It’s a 6GB file so it might take a ‘lil while. I also couldn’t find a single guide online that worked from start to finish, so here I summarise what needs to be done.Īs usual, this is all at your own risk 🙂įirst you need to go to Apple’s OS Download Page and (step 4) get ahold of “InstallMacOSX.dmg” for El-Capitan. 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 use Linux Mint on my main laptop and that was all I had available. I then turned to attempting to make a bootable USB stick of OS X El Capitan from an image downloaded from Apple.

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). The detailed error log says “Chunk validation failed, retrying” about 1000 times and eventually gives up altogether.įurther 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.

#Create bootable usb on mac mac os

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. 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). 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).

Since there wasn’t much worth saving I wiped it and initiated recovery mode in order to re-install OS X (El Capitan). 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.

#Create bootable usb on mac how to

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.