Kernel Panicing on Netboot w/ 2GB of RAM

[apizz]

Can't seem to Netboot any Macbook Pros or MBs with 2GB of RAM. As soon as I take one of the 1GB sticks out and replace with a 2GB stick I'm able to Netboot. This seems really silly though.

Does anyone know why the problem is occurring and know if there's a way around this?

[htse]

does this NetBoot image employ any RAM disks? You might be hitting a ceiling between the amount of RAM needed to startup combined with a RAM disk.

[calumhunter]

usually if its a ram disk issue it just wont boot, or it will boot back to the HD.
But yeah i'd be checking that.

What NBI is it? How was it created? What netboot server are you running?

more details = more help

[apizz]

@calumhunter, more details!

Not 100% familiar with Netboots and netboot terminology, so apologies if I provide information but assign it the wrong term ...

Netboot is running OSX 10.10.5 with Casper 9.73. Created with AutoCasperNBI. All this is stored on a Mac Mini running 10.10.4 with latest Mac mini hardware.

Thanks for the assistance!

[mpermann]

@aporlebeke what options did you select in AutoCasperNBI when you created the NBI?

[davidacland]

I had the same issue a while ago but didn't have time to troubleshoot it. As it was a smaller number of Macs, I enrolled them with recon, then with a policy I added a new 10GB partition, restored the autocaspernbi disk image to it and set that as the startup disk.

They're due for replacement soon so I didn't need to spend more time troubleshooting. This worked around the problem for me.

[calumhunter]

What @mpermann said. What options in AutoCasperNBI did you set, specifically around the rc.netboot ram disk

Is it a particular macbook model? Can you share the model identifier? ie MacBookPro8,1

Does this same NetBoot image works on other devices?

I don't use OS X server for Netboot, I use BSDPy, but I have a 10.10.5 NetBoot image created with AutoCasper NBI and it netboots everything from 2009 white uni body macbooks through to 2015 retina MBP's

It uses a 2GB RAM disk. So even the old 2009 white uni bodies need 4GB ram to play ball (2gb for OS X and 2GB for ram disk)

[bentoms]

Hi all,

As of AutoCasperNBI 1.2.1 the RAM disk is now 1GB.

This was to stop issues people were having with Macs with only 2GB of RAM of VM's (as they default for 2GB).

@aporlebeke you mention AutoCasperNBI & then have posted an image from Apple's System Image Utility. Can you please advise what tool you used & if AutoCasperNBI, what version?

[apizz]

Thanks all. I created the Netboot with AutoCasperNBI 1.2.1. I didn't do anything special with settings, at least not to my knowledge ... see the pics below.

I see the rc.netboot file option is unchecked ... should I have checked that to get my Netboot to work with only 2GB RAM?

[apizz]

Macbook models are Macbook7,1 and Macbook8,1. Don't work with 2GB but work with 3GB. The same actually goes for our older Macbook Pros - MacbookPro9,2 - any older laptops with 2GB of RAM that we've tried.

[mpermann]

@aporlebeke based on your own testing, it doesn't sound like there is anything wrong with your NetBoot set as it works fine if the computers have 3 GB of RAM. You could try ticking the Install Modified rc.netboot file to see if it helps. But since this utilizes a 1GB RAM disk I would think it would only make the problem worse.

Maybe if you create a 10.6.8 NBI it might NetBoot those computers that only have 2 GB of RAM. But you'll likely have to do it the old fashioned way. I suppose it depends upon how many of those model computers you have to image.

You might want to consider doing target mode imaging on those older computers so you can eliminate the NetBoot set.

[bentoms]

@aporlebeke Ignore the whole rc.netboot thing for now.

If the Macs support the OS, they should boot to it. Even with below recommended RAM.

We have the same model MacBooks but with 8GB RAM.

One thing to test, can you recreate the NBI & tick "Create A Restorable DMG" then restore that to a USB disk etc & boot one of the troublesome clients from that.

It'll help us to narrow down if it's an image issue or NetBoot.

[bentoms]

Oh & @aporlebeke another thing to mention, requirements for 10.7+ have largely stayed the same.

For RAM the minimum is 2GB... Whereas for 10.6 it was 1GB.

EDIT: sorry misread some of the Thread. Seems like 2GB works but 3GB wasn't.

[bentoms]

@aporlebeke Lastly, looking at this thread, you might not be using AutoDMG to create your Base OS DMG.

Can you try AutoDMG with the latest 10.10.5 Yosemite installer & then create an NBI via AutoCasperNBI from that?

[apizz]

@bentoms, you are correct I was using Composer to build the base OS. When I have some time, which unfortunately doesn't look like until Thanksgiving or winter break, I will try AutoDMG in making the base OS and then use AutoCasperNBI.

Thanks all!

[apizz]

Recently as a result of of some other issues, I went through and created a new NBI using AutoDMG (OSX 10.10.5) and AutoCasperNBI (both the current versions). Beside the default AutoCasperNBI settings, I checked the rc.netboot file setting.

However, after attempting to image a mid 2010 Mac Mini server I was not able to get it to boot to our Netboot until I put 4GB of RAM instead of the previous 3GB reported. I'm not sure if this is just because of the mini's hardware or what.

This will very soon be a non-issue with all our machines being refreshed this coming summer, but wanted to update.

[taugust04]

This is interesting that this got bumped recently...

I spent three hours trying to get an older 24" iMac to NetBoot to a generic El Capitan Apple NetInstall image over the weekend. We had built one using SIU just for re-imaging Macs that were about to be donated and released from our inventory. I was unable to get Yosemite or El Capitan NetInstall images to work on these systems without a kernel panic. Unfortunately I kept thinking there was something wrong with the image, so I rebuilt them specifically on the hardware having panics, but still wasn't successful. Although I noticed that it had 2GB of RAM installed, I didn't suspect it was a problem because that meets the minimum requirements for Yosemite and El Capitan.

The only thing that did work was a Lion NetInstall that I had initially restricted to older computers that can't run anything newer than that. In addition, I ended up getting a different 24" iMac working with the El Capitan NetInstall - so I just figured the other iMac had some type of issue, considering its age. I'll have to go back now and check what the installed RAM was on the iMac that had no kernel panics NetBooting.

Thanks for bringing this to my attention. JAMFNation frequently has some of the best information for troubleshooting problems for Mac Admins even when its not necessarily a Casper exclusive issue.

[bentoms]

@aporlebeke & @taugust04, interesting.

The rc.netboot option in ACNBI was changed to create a 1GB RAM Disk from 2GB.. this is due to VM's having 2GB by default & was getting reports of errors when NetBooting unless that was lowered.

Not sure why a VM with 2GB will boot to an NBI that a client with the same or a GB more fails. But interesting to see it failing with a SIU built NetInstall.

Guess I'm a little off the hook.