Create Bootable Usb From Dmg El Capitan

Create Bootable USB Installer for Mac OSX Using TransMac. To create bootable USB installer for Mac to Install Mac OS X El Capitan on Windows, on Mac or VirtualBox, you have to create bootable USB flash drive. Let’s get started on how to do it. First, you have to download TransMac software for Windows and install it on your computer.

Introduction

Apple officially released OS X 10.11 El Capitan operating system in September 2015 as an update through Apple App Store. This actualization will update core of your system and preserve your user data.

However, if you want to have a clean installation of El Capitan on your Mac you will need to create a special installation USB drive and in this article we will show you how.

Insert the USB flash drive containing the El Capitan installer into your Mac. Restart your Mac while holding down the option key. After a short delay, your Mac will display the OS X Startup Manager, which will display all of your bootable devices. This should include the bootable USB flash drive you just created.
The most recommendable way to create a bootable install USB drive for Mac OS is using 'createinstallmedia' Command with Terminal application. Step 1: Download macOS or OS X Double click on El Capitan.DMG to mount it, then borrow the El Capitan.app. OS X El Capitan DMG.png711×436 43.3 KB. Choose An 8GB USB thumb drive.
Now using a Windows tool called Transmac (15 day trial) to create a bootable El Capitan USB from the dmg file downloaded from Apple. Will post again with result / subsequent actions / results. Probably the copy of OS X 10.8 I got from a 3rd-party site and used to update 10.6 was dodgy.

Four ways how to create El Capitan USB installation flash drive:

Preparation - get OS X El Capitan installer and USB flash drive

Download El Capitan installer (Install OS X El Capitan.app in Applications folder) available in Mac App Store.

Prepare a flash drive with OS X Disk Utility. Format it with GUID Partition Table and name it as Untitled. The minimal capacity of flash drive must be 8 GB.

How to create El Capitan installation USB drive with createinstallmedia tool

The createinstallmedia is a command line tool distributed with OS X installer.

When you have prepared your USB flash drive and El Capitan installer is downloaded from App Store ► open Terminal and type command:

sudo /Applications/Install OS X El Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install OS X El Capitan.app --nointeraction

In our case 'Untitled' is the name of USB flash drive! Replace 'Untilled' by name of your flash drive.
Wait a few minutes and your El Capitan installation USB drive will be prepared.

To install OS X El Capitan ► restart computer ► hold the Option key and select Installation USB drive from the menu.

How to create El Capitan USB installation with Terminal commands

When your USB flash drive is ready and El Capitan installer downloaded from App Store ► Open Terminal and type the following sequence of commands:

sudo hdiutil attach /Applications/Install OS X El Capitan.app/Contents/SharedSupport/InstallESD.dmg

sudo asr restore -source /Volumes/OS X Install ESD/BaseSystem.dmg -target /Volumes/Untitled -erase -format HFS+

sudo rm /Volumes/OS X Base System/System/Installation/Packages

sudo cp -a /Volumes/OS X Install ESD/Packages /Volumes/OS X Base System/System/Installation/Packages

sudo cp -a /Volumes/OS X Install ESD/BaseSystem.chunklist /Volumes/OS X Base System

sudo cp -a /Volumes/OS X Install ESD/BaseSystem.dmg /Volumes/OS X Base System

hdiutil detach /Volumes/OS X Install ESD

Now wait until your bootable installation flash drive with OS X 10.11 El Capitan is made.

To install OS X El Capitan ► restart computer ► hold the Option key and select Installation USB drive from the menu.

How to create El Capitan USB installation with Disk Utility and Finder

When your USB flash drive is ready and El Capitan installer downloaded from App Store ► Open Terminal and type:

defaults write com.apple.finder AppleShowAllFiles 1 && killall Finder

This command allows you to view hidden files in Finder.

Now Open Finder ► Applications ► Install OS X El Capitan.app ► right click ► Select Show Package Contents option.

Navigate to Contents/SharedSupport ► Mount InstallESD.dmg file

Open OS X Install ESD archive in Finder and mount BaseSystem.dmg archive

Make Bootable Usb From Dmg Mac El Capitan

Connect USB drive and open Disk Utility (/Applications/Utilities)

Select the USB drive from the list of disks, select Restore tab and pick Select OS X Base System archive as a source and USB flash drive as the destination. When ready click on Restore button.

After the Restore process is finished, open Finder ► open USB drive (OS X Base System) ► go to the System/Installation folder and select Packages file and delete it.

Open OS X Install ESD volume in Finder, select Packages folder and copy them to System/Installation folder on USB drive.

Also copy BaseSystem.chunklist and BaseSystem.dmg files from InstallESD.dmg volume to root of USB flash drive (OS X Base System).

Now your El Capitan installation USB drive is prepared and ready for use.

To install OS X El Capitan ► restart computer ► hold the Option key and select Installation USB drive from the menu.

How to create El Capitan USB installation disk with DiskMaker X

DiskMaker X tool is Wizard like tool that allows you create OS X installation disk. Download DiskMaker X to your Mac and copy it to Applications folder.

When you have prepared your USB flash drive and El Capitan installer is downloaded from App Store ► open DiskMaker X.

Select version of OS X (in our case El Capitan)

Select copy of OS X installation app

Select USB drive that will be used for USB installation

And wait a few minutes till the the DiskMaker X finish creating process.

To install OS X El Capitan ► restart computer ► hold the Option key and select Installation USB drive from the menu.

These advanced steps are primarily for system administrators and others who are familiar with the command line. You don't need a bootable installer to upgrade macOS or reinstall macOS, but it can be useful when you want to install on multiple computers without downloading the installer each time.

What you need to create a bootable installer

A USB flash drive or other secondary volume, formatted as Mac OS Extended, with at least 12GB of available storage
A downloaded installer for macOS Big Sur, Catalina, Mojave, High Sierra, or El Capitan

Download macOS

Download: macOS Big Sur, macOS Catalina, macOS Mojave, or macOS High Sierra
These download to your Applications folder as an app named Install macOS [version name]. If the installer opens after downloading, quit it without continuing installation. To get the correct installer, download from a Mac that is using macOS Sierra 10.12.5 or later, or El Capitan 10.11.6. Enterprise administrators, please download from Apple, not a locally hosted software-update server.
Download: OS X El Capitan
This downloads as a disk image named InstallMacOSX.dmg. On a Mac that is compatible with El Capitan, open the disk image and run the installer within, named InstallMacOSX.pkg. It installs an app named Install OS X El Capitan into your Applications folder. You will create the bootable installer from this app, not from the disk image or .pkg installer.

Use the 'createinstallmedia' command in Terminal

Connect the USB flash drive or other volume that you're using for the bootable installer.
Open Terminal, which is in the Utilities folder of your Applications folder.
Type or paste one of the following commands in Terminal. These assume that the installer is in your Applications folder, and MyVolume is the name of the USB flash drive or other volume you're using. If it has a different name, replace MyVolume in these commands with the name of your volume.

Big Sur:*

Catalina:*

Mojave:*

High Sierra:*

El Capitan:

* If your Mac is using macOS Sierra or earlier, include the --applicationpath argument and installer path, similar to the way this is done in the command for El Capitan.

After typing the command:

Press Return to enter the command.
When prompted, type your administrator password and press Return again. Terminal doesn't show any characters as you type your password.
When prompted, type Y to confirm that you want to erase the volume, then press Return. Terminal shows the progress as the volume is erased.
After the volume is erased, you may see an alert that Terminal would like to access files on a removable volume. Click OK to allow the copy to proceed.
When Terminal says that it's done, the volume will have the same name as the installer you downloaded, such as Install macOS Big Sur. You can now quit Terminal and eject the volume.

Create Bootable Usb From Dmg El Capitan Mac

Use the bootable installer

Determine whether you're using a Mac with Apple silicon, then follow the appropriate steps:

Apple silicon

Plug the bootable installer into a Mac that is connected to the internet and compatible with the version of macOS you're installing.
Turn on your Mac and continue to hold the power button until you see the startup options window, which shows your bootable volumes and a gear icon labled Options.
Select the volume containing the bootable installer, then click Continue.
When the macOS installer opens, follow the onscreen instructions.

Intel processor

Plug the bootable installer into a Mac that is connected to the internet and compatible with the version of macOS you're installing.
Press and hold the Option (Alt) ⌥ key immediately after turning on or restarting your Mac.
Release the Option key when you see a dark screen showing your bootable volumes.
Select the volume containing the bootable installer. Then click the up arrow or press Return.
If you can't start up from the bootable installer, make sure that the External Boot setting in Startup Security Utility is set to allow booting from external media.
Choose your language, if prompted.
Select Install macOS (or Install OS X) from the Utilities window, then click Continue and follow the onscreen instructions.

Learn more

For more information about the createinstallmedia command and the arguments that you can use with it, make sure that the macOS installer is in your Applications folder, then enter the appropriate path in Terminal:

Big Sur: /Applications/Install macOS Big Sur.app/Contents/Resources/createinstallmedia
Catalina: /Applications/Install macOS Catalina.app/Contents/Resources/createinstallmedia
Mojave: /Applications/Install macOS Mojave.app/Contents/Resources/createinstallmedia
High Sierra: /Applications/Install macOS High Sierra.app/Contents/Resources/createinstallmedia
El Capitan: /Applications/Install OS X El Capitan.app/Contents/Resources/createinstallmedia

A bootable installer doesn't download macOS from the internet, but it does require an internet connection to get firmware and other information specific to the Mac model.