This is comprehensive guide to create Mac OS X Bootdisk installer.

The guide uses VM but it should work the same on physical disk.

Pre-requisites:

1. Download Mac OS X 10.10 Yosemite from Apple Store

2. Create a new Virtual HDD with at least 8 GB

3. Open Terminal (Mac HDD -> Applications -> Utilities -> Terminal)

4. In Terminal, execute below command for Finder to show All files

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

For detail, please refer to Mac OS: Set Finder to Show All Files

 

Step 1: Mounting Mac OS Installer DMG

1. Open Finder, select Mac HDD

2. Navigate to Applications -> Install OS X Yosemite

3, Right click on Install OS X Yosemite, and select Show Package Contents

1. In Install OS X Yosemite mounted volume, Expand Contents -> SharedSupport

2. Right Click on InstallESD.dmg and select Open With -> DiskImageMounter (default)

1. In OS X Install ESD, right Click on BaseSystem.dmg, and select Open With -> DiskImageMounter (default)

Steps 2: Create Bootdisk Partition

1. Open Disk Utility (Mac HDD -> Applications -> Utilities -> Disk Utility)

2. Select harddisk for Bootdisk and select Partition tab

 3. On Partition Layout, click on + button to add new partition

1. Change Partition Name to Bootdisk, and click Apply button

1. Click on Partition to proceed

 

Step 3: Create Mac OS X Bootdisk

1. Open Disk Utility (Mac HDD -> Applications -> Utilities -> Disk Utility)

2. Navigate to Bootdisk HDD -> Bootdisk Volume, select Restore tab

1. Drag and Drop Bootdisk Volume to Restore Destination textbox

1. Click on BaseSystem.dmg to show on Restore Source textbox

1. Click Restore button and click on Erase button

1. Enter Password if prompt

1. Restore will proceed

Note: Bootdisk Volume name will be also renamed as OS X Base System

 8. Right Click on Bootdisk Restore Volume and select Reveal “OS X Base System” in Finder

1. In Finder, Right click on highlighted file OS X Base System and select Get Info

1. On Name & Extension section, Rename to Mac OS X 10.10 Yosemite Bootdisk and press ENTER

1. Copy Packages from OS X Install ESD Mounted Volume to Bootdisk

1. Once Packages Copy is completed, Eject mounted volume used to create bootdisk

1. Open Terminal, execute below command to revert Finder Show All Files to default setting

defaults write com.apple.finder AppleShowAllFiles 0 && killall Finder

For detail, please refer to Mac OS: Set Finder to Show All Files