Target Mode Imaging

Target Mode Imaging (TMI) allows you to image multiple computers consecutively by connecting them to a host computer using a FireWire or Thunderbolt cable. This can be ideal when using a network connection is not optimal.

To use TMI, you run Casper Imaging on a host computer. Then you boot the computers being imaged (target computers) to target disk mode and connect them to the host computer.

This section provides a basic, best practice workflow for imaging computers by using TMI.

Best practices for TMI differ based on the scope of the project. Consider the following when planning your TMI project:

  • Number of staff available

  • Number of target computers

  • Number of host computers available

  • Time constraints
    Note: It is recommended that you set up a test environment prior to the project's start date to help estimate how long it will take to complete the project in each unique environment.

Requirements

To use TMI, you need:

  • Target computers that support target disk mode

  • A host computer with Casper Imaging installed and a FireWire or Thunderbolt port
    Note: It is recommended that you use a dedicated host computer for TMI.

  • A configuration with a base image and packages
    If you have not created the configuration or base image yet, see Create a Configuration with a Base Image and Packages for detailed instructions.

  • A distribution point
    While you can use a file share distribution point on the network, it is recommended that you use a local distribution point for optimal data transfer speeds. (For detailed instructions, see Create a Local Distribution Point.)

  • A Thunderbolt to Thunderbolt cable (recommended) or FireWire cable

  • A naming scheme (For more information, see Naming Scheme.)

Before You Begin

The following instructions will help you prepare for imaging.

Note: If asset stickers need to be applied to new computers, consider applying them during the TMI project.

Create a Configuration with a Base Image and Packages

Configurations allow you to quickly specify what needs to be installed and configured on computers during imaging. Configurations can be created using the JAMF Software Server (JSS) or Casper Admin.

Note: It considered best practice to use configurations when imaging computers using TMI. However, if you are not using configurations, click Show Custom in Casper Imaging and then use the tabs and options to customize the imaging process.

If you need a base OS image, see Creating a Minimal Base OS Image for detailed instructions.

Using the JSS to Create a Configuration

  1. Log in to the JSS with a web browser.

  2. In the top-right corner of the JSS, click Settings.

  3. Click Computer Management.

  4. In the "Computer Management" section, click Configurations.

  5. Use the General payload to configure basic settings for the configuration.

  6. Use the Packages, Scripts, Printers, and Directory Bindings payloads to add items to the configuration.

  7. Use the Management payload to set or create a management account.
    This ensures that computers imaged with the configuration are managed.

  8. Click Save.

Using Casper Admin to Create a Configuration

  1. Open Casper Admin on the host computer.

  2. Select "New Config ".

  3. Enter basic configuration information.

  4. Click Save.

  5. Drag packages from the right pane to the configuration in the sidebar.

For more information, see Configurations in the Casper Suite Administrator's Guide.

Create a Local Distribution Point

A local distribution point created on the host computer can greatly increase the efficiency and speed of the imaging process.

  1. Create a new folder in the root of the host computer's main hard disk.

  2. Open Casper Admin on the host computer.

  3. Drag a folder from the host computer into the sidebar of Casper Admin.

  4. Select the folder in the sidebar and click Replicate.
    Note: The entire distribution point will be replicated to the host computer's drive. Be aware of available space on the drive.

  5. When replication to the local folder is complete:

    1. Select "Choose Local Drive" from the Distribution Point pop-up menu in Casper Imaging and browse to the Local Distribution Point folder.

    2. Click Choose.

  6. In the main Casper Imaging window, verify that the Distribution Point displays the path to the Local Distribution Point folder.

Naming Scheme

You can use Casper Imaging to specify how to assign names to target computers when imaging computers using TMI.

  1. Open Casper Imaging on the host computer.

  2. From the Computer Names pop-up menu, choose how to assign names to target computers:

    • To be prompted to manually enter a name for each computer, choose "Prompt for Each Computer".

    • To automatically generate names in numerical order, choose "Use Numerical Order". Then enter a starting number, and a prefix and suffix as needed, and click OK.

    • To use each computer's MAC Address as the name, choose "Use MAC Address". Then enter a prefix and suffix for the MAC Address as needed and click OK.

    • To use each computer's serial number as the name, choose "Use Serial Number". Then enter a prefix and suffix for the serial number as needed and click OK.

    • To assign names based on the contents of a CSV file, choose "Upload CSV File" and upload the file.
      For more information, see Creating a CSV File to Assign Computer Names During Target Mode Imaging.

Imaging Computers

You can use TMI to image a single target computer or multiple target comp uters consecutively.

Image a Single Target Computer

Imaging a single target computer involves the following steps:

  1. Prepare the host computer.

  2. Image the target computer.

Step 1: Prepare the Host Computer

  1. Ensure no computers are connected to the host computer.

  2. On the host computer, open Casper Imaging and authenticate locally.

  3. Authenticate to the JSS when prompted.

  4. Choose “Target Mode Imaging” from the Target Drive pop-up menu.

  5. Choose the naming scheme from the Computer Names pop-up menu.

  6. Choose a configuration from the Configuration pop-up menu.

  7. Choose the distribution point from the Distribution Point pop-up menu.

  8. From the Computers Will Check In with JSS pop-up menu, choose the approximate amount of time until computers check in with the JSS.
    Select a larger value if you are unsure how long it will take for the computers to get an internet connection and check in with the JSS. If the enrollment window expires, computers will need to be enrolled in the JSS using a different method.

Step 2: Image the Target Computer

  1. Verify the settings are correct in Casper Imaging and click Start .
    Warning: Casper Imaging begins to look for connected computers at this point.

  2. Boot a target computer to target disk mode.
    To do this, turn on the computer and immediately press and hold down the T key until a FireWire or Thunderbolt symbol is displayed.

  3. Use a FireWire or Thunderbolt cable to connect the target computer to the host computer, and then click OK if prompted.
    The imaging process starts immediately.
    If configured to prompt for computer name, Casper Imaging prompts for the new computer name.

  4. When the imaging process is complete, disconnect the target computer.
    The target computer will attempt to connect to the JSS at startup and then every 5 minutes until it successfully enrolls the computer.

Image Multiple Target Computers

You can use TMI to image multiple target computers. The imaging station method is ideal for environments in which the target computers are easily moved. The mobile host computer method is intended for environments in which a portable computer can be used as the host computer and carried to each target computer.

Regardless of which method you use, imaging multiple target computers involves the following steps:

  1. Prepare the host computer.

  2. Image the target computers.

Imaging Station Method

If the target computers are able to be moved easily, it is possible to set up one or more imaging stations to perform the TMI process. In addition, multiple imaging stations can be implemented if multiple staff members are available.

Note: To avoid network strain, it is recommended that you use a local distribution point when using multiple imaging stations. (For detailed instructions on how to create a local distribution point, see Creating a Local Distribution Point.)

Step 1: Prepare the Host Computer

  1. Set up a dedicated table for the host computer (the imaging station).

  2. Ensure no computers are connected to the host computer.

  3. On the host computer, open Casper Imaging and authenticate locally.

  4. Authenticate to the JSS when prompted.

  5. Choose “Target Mode Imaging” from the Target Drive pop-up menu.

  6. Choose the naming scheme from the Computer Names pop-up menu.

  7. Choose a configuration from the Configuration pop-up menu.

  8. Choose the distribution point from the Distribution Point pop-up menu.

  9. From the Computers Will Check In with JSS pop-up menu, choose the approximate amount of time until computers will check in with the JSS.
    Select a larger value if you are unsure how long it will take for the computers to get an Internet connection and check in with the JSS. If the enrollment window expires, computers will need to be enrolled in the JSS using a different method.

Step 2: Image the Target Computers

  1. Bring the target computers to the table.

  2. Boot a target computer to target disk mode.
    To do this, turn on the computer and immediately press and hold down the T key.

  3. Use a FireWire or Thunderbolt cable to connect the target computer to the host computer, and then click OK if prompted.
    The imaging process starts immediately.

  4. When the imaging process is complete, disconnect the target computer.
    The target computer will attempt to connect to the JSS at startup and then every 5 minutes until it successfully enrolls the computer.

  5. Proceed to image target computers in assembly line fashion by repeating steps 2–4, and then returning the target computer to the desired location (either boxes for storage or to a physical location).

Mobile Host Computer Method

If it is more practical to leave the target computers in place, a portable computer can be used as the host computer and carried to each target computer.

Multiple host computers can be in used in this scenario.

Warning: Leave the host computer plugged in to a power source for the duration of this procedure. Imaging is a power intensive process, and a power failure during the TMI process may cause data loss.

Step 1: Prepare the Host Computer

  1. Set up the host computer on a portable computer.

  2. Ensure no computers are connected to the host computer.

  3. On the host computer, open Casper Imaging and authenticate locally.

  4. Authenticate to the JSS when prompted.

  5. Choose “Target Mode Imaging” from the Target Drive pop-up menu.

  6. Choose the naming scheme from the Computer Names pop-up menu.

  7. Choose a configuration from the Configuration pop-up menu.

  8. Choose the distribution point from the Distribution Point pop-up menu.

  9. From the Computers Will Check In with JSS pop-up menu, choose the approximate amount of time until computers check in with the JSS.
    Select a larger value if you are unsure how long it will take for the computers to get an Internet connection and check in with the JSS.

Step 2: Image the Target Computers

  1. Boot a target computer to target disk mode.
    To do this, turn on the computer and immediately press and hold down the T key.

  2. Use a FireWire or Thunderbolt cable to connect the target computer to the host computer, and then click OK if prompted.
    The imaging process starts immediately.

  3. When the imaging process is complete, disconnect the target computer.
    The target computer will attempt to connect to the JSS at startup and then every 5 minutes until it successfully enrolls the computer.

  4. Move the host computer to each target computer and repeat steps 1–3.

Post-imaging Enrollment

After target computers have been imaged, they can be stored or turned on.

If the computers are stored immediately, they are not enrolled with the JSS until the next time they are turned on. Any issues enrolling computers with the JSS will not be discovered until the day of the rollout, and must be resolved at that time. This method completes the TMI process in the fastest time.

If the computers are immediately turned on, they are automatically enrolled with the JSS and successful enrollment can be verified. Using this method, it is possible to verify that the computers are fully prepared for the rollout day.

Troubleshooting

Target computers not detected by Casper Imaging

If target computers are not detected during the "Searching for Computers" phase:

  1. Verify that both ports are Thunderbolt-capable.

    • The label on the port should be the Thunderbolt symbol (lightning bolt).

    • Use the System Information to determine if the computer is Thunderbolt-capable.

  2. Unplug the Thunderbolt cable from the target computer, wait 10 seconds, and then re-insert the cable.

Note: A variety of issues may occur if imaging is done on multiple target computers in succession using a single host computer. Regularly scheduled reboots after imaging 2-5 target computers can help resolve imaging issues that arise. The number of target computers that can be imaged between reboots can vary based on the host computer.

Packages missing from the imaged computer

If packages are missing or don't deploy during imaging:

  1. Verify the packages are listed on the sidebar of Casper Imaging prior to clicking "Image".

  2. To determine whether a specific package is causing the issue: Deploy the package to a test computer that is not part of the imaging process and ensure the intended results are achieved.

  3. Use the JSS to check the Casper Imaging logs for the target computer.

    For more information, see "Viewing Casper Imaging Logs for a Computer" on the Viewing the History for a Computer page in the Casper Suite Administrator's Guide.

Casper Imaging Debug Mode

If you are not able to resolve TMI issues, put Casper Imaging into full debug mode and contact your Technical Account Manager (TAM). Putting Casper Imaging into debug mode will help your TAM identify the issue. To put Casper Imaging into full debug mode, execute the following command on the host computer and then reopen Casper Imaging: 

sudo touch /Applications/Casper\ Suite/Casper\ Imaging.app/Contents/Support/debug

When full debug is enabled in this way, a log is created on the target computer. This log can be found in the following location:

/Library/Logs/JAMF/ImagingScripts.log

A debug log is also created on the host computer running Casper Imaging. This log can be found in the following location:

~/Library/Logs/JAMF/CasperImagingDebug.log

Logs and any screenshots of the issue are also helpful. From the target computer, the logs to provide are:

  • /var/log/system.log

  • /var/log/jamf.log

  • /var/log/install.log

From the JAMF Software Server, the log to provide is:

/path/to/jss/logs/JAMFSoftwareServer.log

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