Casper Imaging 9.81 Erase Disk failing

Have you tried manually erasing by netbooting and then opening disk utility and then erasing? I also had to turn off the search function to be able to unmount said disk. I also had issues erasing a FV2 enabled drive (didn't expect to have that issue). I had to decrypt before anything could be done.

I can erase the drive in a netboot instance with either a standard diskutil command (I do this for FV2 encrypted disks as well so I won't have to decrypt) or via an empty pass with Casper Imaging (choose erase disk and leave configuration empty) and both will erase the disk correctly. But when choosing Erase Disk and then a configuration (custom or not) everything applies including hostname set and preference clearing, but the disk is not erased and everything is just laid over top.

This is the command I run to purge FV2 drives:
diskutil eraseDisk JHFS+ Macintosh HD /dev/disk0

Interesting. Still doesn't work for me. I've used those commands and it still fails stating that it cannot unmount disk. I'm still running 9.65, so I don't know. Might be a version issue? We're slated to upgrade over thanksgiving, so we'll see how that goes.

Is your Netboot instance one captured with SIU or made via AutoCasperNBI?

SIU. We didn't go with the AutoCasperNBI because the guy that managed this before "couldn't ever get it to work." I haven't had control of our environment for very long.

@Chubs you should give @bentoms AutoCasperNBI a go. It's super easy to use. You can use AutoDMG to create a nice clean base OS and use that in the build process. I used to dread making new NBI sets, but with AutoCasperNBI, it's a snap.

@mpermann We use AutoDMG for our OSs. My previous employer, we made fat ASR images to deploy. This is a different "a la carte" concept with Casper that I seem to like a lot more.

I'm going to check into the AutoCasperNBI after our JSS/Casper upgrade in the next month or so.

There was another jamfnation thread that I forget, but it said if you're imaging a Mac with Recovery HD present, you may need to bless the drive. I have the script below added to my imaging config.

"#!/bin/sh
bless -mount /Volumes/Macintosh HD -setBoot"

If you have to do bless, please report it as a bug - maybe it'll have better chance of getting fixed.

My original thread

That Defect number is D-009763

The issue isn't with bless booting on these machines as they're all initiated manually on the same subnet. Imaging occurs correctly after everything is pulled on to the machine and it is restarted, but the the Erase Disk portion does not apply within the task sequence - for lack of a better word - unless that task sequence is empty. Installing everything onto a blank drive (erased with diskutil) before hand lets everything complete as expected.

@andrew.nicholas we've had similar problems. Instead of relying on Casper Imaging to do the erase we do it using a script. Have a look at my post at the bottom of this thread for how we are doing it.

Thanks @mpermann, I was pretty sure that's where I was going to have to head; at least for the interim.

I'm just realizing that this has been happening to us as well and I never knew. Reimaging computers we check the erase target drive option, and then it's supposed to laydown a compiled image, however if I don't erase it first it seems to fail enrollment. Frustrating. Anyone see an open defect for this?

Gabe Shackney
Princeton Public Schools