Mac OS X Server: How to Upgrade Mac OS for NetBoot Clients

This article tells how to upgrade the version of Mac OS used by NetBoot Clients, and how to deal with Mac OS ROM startup issues that may arise during the process.

This article assumes the reader is familiar with using NetBoot Desktop Admin to upgrade the images used by the NetBoot Clients. If not, consult the NetBoot Desktop Admin Read Me before continuing.

Create the private images

1. Log on to a NetBoot client computer as a Global Administrator who belongs to the System Access workgroup.

2. Connect to the NetBoot Server volume. Open the NetBoot Desktop Admin application program.

3. Using NetBoot Desktop Admin, increase NetBoot HD.img image so that there is at least 250 MB of free space. (You cannot reduce the size of an image without reverting to a backup copy.)

4. Click Make Private Copy. NetBoot Desktop Admin creates copies of the disk images that you can change. This may take several minutes; you should not interrupt the process. When it finishes, your NetBoot client computer restarts automatically. The disk images have been copied to the client's folder.

Upgrade Mac OS

5. Upgrade Mac OS using the Installer. You may want to perform a custom installation because some Mac OS installers offer a custom installation of additional software for NetBoot clients. After the upgrade, the computer does not need to be restarted.

The next time the client starts up it downloads the old Mac OS ROM from the SharedImages folder on the server but attempts to start up with the new version of Mac OS.

If the client no longer starts up

6. Start up the client from the CD you used to upgrade Mac OS.

7. Log in to the NetBoot Server as an administrator using the Chooser.

8. Locate and open the SharedImages folder.

9. Rename the Mac OS ROM in the SharedImages folder; it may be needed later. (For example, name it "Mac OS ROM-Previous".)

10. Copy the Mac OS ROM file from the System Folder on the CD to the SharedImages folder.

11. Restart the client from the NetBoot server again.

Saving changes

12. After the client restarts, log in to the NetBoot server as an administrator.

13. Open NetBoot Desktop Admin, and click Save to save the new images. The system restarts and the disk images in the client's folder now have '+' appended to them.

If you had to do steps 6 through 10 again the computer may not restart. This is because the computer restarts from the original images, but the Mac OS ROM file has been upgraded.

If the computer does not restart again

14. Start up the client from the CD again.

15. Log in to the server as an administrator.

16. Locate and open the SharedImages folder.

17. Rename Mac OS ROM file; it may be needed later. (For example, name it "Mac OS ROM-New".)

18. Rename the Mac OS ROM file from step 9 back to "Mac OS ROM".

19. Restart the client from the NetBoot server.

Using the newly updated images

20. Log in to the server as an administrator.

21. Open NetBoot Desktop Admin.

22. Click Restart after choosing whether to save the previous images. This moves the images in the SharedImages folder, moves the images from the client's folder to SharedImages, and renames them properly.

23. Verify that the file named Mac OS ROM in the SharedImages folder is the correct version for the version of Mac OS just installed. You can do this by selecting the files and choosing Get Info from the Finder's File menu.

All clients should now start up using the updated images.

Published Date: Feb 17, 2012