Creating a OS X NetInstall Image using System Image Utility.
Use System Image Utility to create a NetInstall image that you can use to install software on client computers over the network. You can find this application in the /System/Library/CoreServices/ folder.
To create an image, you must have valid OS X image sources or volumes. If you download OS X installer from the App Store and double-click it, a valid OS X image source appears in the source list. You cannot create an image of the startup disk you’re running on.
Log in as an administrator user.
Open System Image Utility (in the /System/Library/CoreServices/ folder).
In the left sidebar, select the image source.
Select NetInstall Image and click Continue.
In the Network Disk field, enter a name for your image.
This name identifies the image in the Startup Disk preferences pane on client computers.
(Optional) In the Description field, enter notes or other information to help you characterize the image.
Clients can’t see the description information.
If the image is served from more than one server, select the checkbox below the description field.
This assigns an index ID to the image for NetInstall service load balancing.
Click Create.
In the Save As dialog, choose where to save the image.
If you don’t want to use the image name you entered earlier, change it by entering a name in the Save As field.
If you’re creating the image on the same server that will serve it, choose a volume from the “Serve from NetBoot share point on” pop-up menu.
For this option to appear in the pop-up menu, NetInstall service must be configured on a network port and ther Server app must be set to serve images from a volume.
To save the image somewhere else, choose a location from the Where pop-up menu or click the triangle next to the Save As field and navigate to a folder.
Important: Don’t attempt to edit content in the image destination folder while the image is being created.