Not applicable

Hello all,

I am just looking for some info regarding netboot. We are utilizing netboot with about a 4 or 5GB image. We are also erasing the HD on boot to casperimaging. From experience what are you all experiencing as far as completion time on the newer Macbooks.


Not applicable

Hey Shannon,
Have not seen a difference in the amount of time taken to image a new
MacBook Pro over an old iMac or newer iMac.

Are you loading packages or just laying down an image?


Not applicable

Just the IMG. It takes an hour and half to 2 hours. we are on a separate VLAN for this netboot stuff. Now that i have that info I need to see what the hold up in the netboot is.

Not applicable

What speed is your network?


Honored Contributor III
Honored Contributor III

do you have ppc & intel images?

Not applicable

GigE network

Not applicable

My casper is running on a MAC mini and have not monitored performance there as the image process runs.

Not applicable

1.5 –2 hours is way, way, too long for just a 4GB base image even if you are going across a fast-Ethernet network. Normally our offices can image in about 40 minutes- less if they are on a 1 gig network.

Question: is your distribution point also your netboot server? If it is, that can slow imaging down significantly.

You might also try compiling your builds- this can save a huge amount of time.



Not applicable

Could it be related to the load on the server? how many machines are imaging at the same time?


Amir Hussain
IT Analyst (Mac Services)
LIS Development
Software Management Team
University of Central Lancashire
Ext. 5050
01772 895050

Contributor II

What is doing the routing for this NetBoot service? How far apart (logically, physically) are these two networks?

Do you have asr scan the config/image for multicast? If so, how did you create and scan the image?

How fast are your pings from the target network to the NetBoot server?

Cheers, - Douglas Worley

Sent from my Tricorder.

Honored Contributor

I image 10 laptops at a time off my Mac Mini and my Image is just under 10gigs. It is on a gig switch. Takes me about 25 minutes to image 10.

Not applicable

Honestly I think we have network congestion. I am going totry moving my Casper server into a more direct path with our imaging lab and see if I can clear it out.

Not applicable

OK after spending my day trying to figure out the netboot, our network group sniffing the network, it appears that we are unicasting the image. there are some multicast packets, but they done't appear to be the preferred delivery mechanism. I have read on multicast images and it appears that requires client side command line stuff. If we are wanting to use CasperImaging suite to deliver the base.dmg image we are providing, can we deliver that multicast.
I just did an asr scanimage --source <path/to/base.dmg> (I left off the --nostream because that sets the image up for unicast if I am reading correctly) and am waiting on the netboot results. Am I lost here or headed in teh right direction?

Contributor II

The man page for asr is confusing. It used to be actually wrong. :)

When scanning an image in Disk Utility, it adds the --nostream option which optimizes it for unicast deployment. The assumption is that if you are using a GUI app, you want unicast.

The default in the CLI using asr is to not put the --nostream option, which optimizes it for multicast deployment. The assumptions here is that if are using the CLI you are a power user, and likely want multicast.

The good news is that ASR will restore even if the image is scanned with the incorrect method, just so long as it is scanned. The news that your image is taking forever and throwing up multicast packets is in line with my labs of this use case.

Try making a copy of the image, and scan that with the --nostream option. See if that makes any difference.

Best of luck! - Douglas

Not applicable after scanning the copied image there is still no change. Is there something i am missing on the server to set up?

Contributor II

Try restarting the NetBoot service?

Is there any pattern in the network traffic? Like, does the traffic show up only when pushing an image, or when sitting idle while NetBoot screen?

Did you use the Resource Kit to create the .nbi? Try making a new JAMF netboot set, see if that makes any difference.

Valued Contributor II

I followed the netboot instructions from the "Casper Netboot Automator
Action.pdf" and I can't get it to work..

When I start system image util, I have 2 x Install Mac OS X Lion options
and 2 x Mac OS X Lion options...

Today I also had 1x of the ESD options...

It follow steps for configure options (Configure automatic root login,
launch casper imaging, and preference file) but when I try the netboot
it just launches a clean install complete with choose your regions...

John Wojda

Lead System Engineer, DEI & Mobility

3333 Beverly Rd. B2-338B

Hoffman Estates, IL 60179

Phone: (847)286-7855

Page: (224)532.3447

Team Lead DEI: Matt Beiriger
<mailto:mbeirig at;jwojda at

Team Lead Mobility: Chris
<mailto:cstaana at;jwojda at
edback&body=I%20am%20contacting%20you%20regarding%20John%20Wojda.> Sta

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