Creating a NetRestore Image from a InstaDMG .dmg

[Paul Bloch]

I’ve got InstaDMG working. Thanks, it’s a great tool. I can take my dmg and using Software Image Utility create a NetRestore Image. This I can move to our NFS server and then net boot a Mac and have it restored from my created image. All very close to what I want. The next step is to remove Software Image Utility from the picture and have a command line way to perform the same operation. Then I can go to the InstaDMG directory and type `make` and my images will get created, changed to NetRestore Images and placed in the proper location on our server.

I can’t find the command line alternative to the GUI Software Image Utility. Is there a command line tool for that?

[larkost]

This all depends on what you want.

System Image Utility (SIU) does not directly have a command line option. However, the components that make up SIU are all useable from within Automator, and saved Automator actions can be called from the ‘automator’ command line utility. You can even put in some variables from the command line for things that can have Automator variables. So you can construct yourself a nice little work-flow from that.

At one point I tried arrange things so that I could use a SIU workflow as a back-end for InstaUp2Date (an optional one). However there are some real holes in this as a useable work-flow:

1) You have to choose all of the the items that you are going to have installed right from the start, and none of them can be in .dmg’s. The workflow will save hard-coded paths to the items you choose. This throws automated setup (ala InstaUp2Date) right out the window. I tried reverse-engineering the data structure that the workflow items pass between themselves, but this one bit is a bit opaque (passes a memory address to something).

2) You can use a .dmg as the OS source for creating the image, but you have to mount it yourself before calling the process. You can use a variable for the path, so there is some flexibility here.

3) Error handling is really bad. If something goes wrong you are not going to be able to reliably report what.

4) For the source volume you have to pass in a mounted volume location. And it will do all of the work of making a dmg and then scanning it.

But there are a couple of alternatives:

1) I was given the idea that one could create a package at a specific location that would be a meta-package pointing to the things you actually want to install. Then include just this package in the workflow. And change the package as desired. Workable, but not really a solution I liked.

2) Some folks over at the University of Edinburgh were working on [url=https://www.wiki.ed.ac.uk/display/DSwiki/Automating+the+creation+of+NetBoot+images]InstaNBI[/url], and had something working.

3) You could create the NBI set with a canned SIU workflow, and have it create a NetRestore image from a blank dmg file (to speed things up). Then you could open the NBI folder up, open the image inside, and replace the System.dmg file with one that you made with InstaDMG.

4) If you comb through how Mike Bombich’s NetRestore script works it would be fairly easy to create your own version of that information… but that is going to take a lot of testing.

PS… I have submitted a number of radars to Apple on this, and largely had them turned down. I have also had a couple of conversations with the manager in charge of SIU at Apple, but have yet to bring him to my way of thinking on these things. I will try more the next time I see him.

[Author]

Posts