Netboot Casper imaging not copying or installing package when "erase target drive" option is set

[dommer]

Still fairly green to the Mac world and Casper.
Not sure if it is coincidental, since upgraded to Casper 9.32 and NetSus to 3.01 (running netboot image 10.8.5), we can no longer run Casper imaging, failed with "An exception of class NilObjecException was not handled. The application must shutdown”. As we have not been running Casper imaging for over 6 months, think time to upgrade the Netboot image to 10.9.4, as most our machines are now on 10.9x.
Build the minimal Base OS as per https://jamfnation.jamfsoftware.com/article.html?id=313. And set up root account and Casper imaging as per https://jamfnation.jamfsoftware.com/article.html?id=307. Test run the image from USB drive with Casper imaging, with success.
Unfortunately unable to use Casper NetInstall Image Creator v4.0 to build Netboot image, as it only support afp share for distribution, and our current setup is using smb share for the distribution. (https://jamfnation.jamfsoftware.com/article.html?id=74)
Instead, I used OSX "System Image Utility" to create the netboot image. I have also manually edit the NBimageinfo.plist, and changed “Support diskless” option to “true”. (which I read it in one of the post in this forum). And successfully boot up (via Casper netsus), and mount the distribution with smb. Unfortunately during the imaging process with the “erase target drive” option ticked, it just skipped the steps to copy the dmg or installing packages, and go straight to rename the computer etc., and stuck there. Whereas, if I erase the target drive with disk utility before netboot, the imaging process completed successfully.
Hope if anyone here can help me if I have missed anything and point me to the right direction.
Thanks in advance.

[dommer]

Searching through this forum, I suspect the cause of my issue is due to my netboot image is not diskless.
But most of the discussion and means of making the image diskless is on the netboot image being hosted on a MacOSX server.
Appreciate if someone can tell me how to make the image diskless if that is being boot from a Casper Netsus appliance.
Thanks in advance.

[daz_wallace]

Hey Dommer,

If you connect to the NetSUS as you normally would to upload a new NBI image, find the "NBImageInfo.plist" file inside the NBI folder and open this is Textwrangler or TextEdit (on plain text mode).
Find the line:
"SupportsDiskless" and change the value from "<false/>" to "<true/>"
Save. Close. Unmount the share.
In the web interface: T.urn the netboot service off, wait 30 seconds and turn it on again

That should do it. One thing to bare in mind is if there is no or very little free space left on your NetSUS, than no matter what you do here, it won't be diskless as it won't have the space to store the Netboot client files. I'm starting to recommend 300 GB (250 GB minimum) for all NetSUS systems that are both Netboot and SUS.

Hope that helps!

Darren

[dommer]

Hi, Darren,
Thanks for your response. I already changed the value for "SupportDiskless" from <false> to <true>, before upload the NBI to the Netsus Appliance, as mention in this discussion (https://jamfnation.jamfsoftware.com/discussion.html?id=4158). I have tried to turn the service off and on as suggested, and also tried reboot the appliance, and in both cases, made no difference.
There is plenty of free space in my Netsus Applicance, as it was newly built, and I have stopped (since built) "Store software updates on the NetBoot/SUS server". Only the NBI image are stored in the Netsus appliance for the moment. With over 150G free disk space.
I noticed that if I used Casper Netinsall Image Creator to build the NBI from the same base image, it is definitely built or run as diskless, as I was able to dismount the target disk before the Casper imaging started. Unfortunately I am unable to use this NBI as our DP is using SMB (from a window share).
Whereas if I used the OSX SIU to build the NBI from the same base image, I was unable to dismount the target drive, even with the force option. I suspect that is the cause for the failure of the erase and block copy for the imaging, if the "erase target drive" option is set. Which require (I assume) the target drive need to be dismount for the erasure and block copy.
I have also notice the difference on the mount point of the target drive on the two NBI. The NBI created using Casper Netinstall has the target drive mounted as /Volumes/MacIntosh HD; Whereas the OSX SIU created NBI mounted the target drive as /private/var/netboot. Not sure if that difference in mount may have caused the problem.

[dommer]

Darren,
From this article:http://support.apple.com/kb/TS4316, it clearly said that:

The following output is an example of an unsuccessful diskless NetBoot (the shadow file is stored on the client).

/dev/disk0s2 on /private/var/netboot

which is exactly what I am experiencing. And editing the NBImageInfo.plist, don't seem to have any effect on the Netsus Appliance to boot the NBI in diskless either.
Any suggestion please. Thanks in advance.

[dommer · Accepted solution]

I have answeered my own question.
End up following this solution, and create a ramdisk for the netboot.
http://www.macos.utah.edu/documentation/administration/setup_netboot_service_on_mac_os_x_10.6.x_client.x_client/setup_netboot_service_on_mac_os_x_10.6.x_client-diskless_netboot.html
Casper imaging able to dismount the target drive for block copy now,and imaging is now working fine.