Netboot not allowing Mac HD to unmount

[chutiya]

Hi all,

we have an issue where, when netbooting and asking disk utility to partition/erase/unmount the Macintosh HD, there is an error that the disk can not be unmounted.

Anyone had this before? Any solutions please?

The Mac OS used to create the NBi is 10.9.

If you'd like any more information let me know.

thanks in advance for any help/suggestions.

[jwojda · Accepted solution]

see this - https://jamfnation.jamfsoftware.com/discussion.html?id=5416 - It talks about 10.6, but I've used it on 10.7 and 10.8... and since I'm seeing it in 10.9's, I'm starting to move the file into there -

In certain, situations you never want use a clients local disk for the NetBoot shadow file, like if you want to run hard disk utilities like Disk Utility or Disk Warrior, or for us if we want to run the file system maintenance software we use, radmind, out-of-context. Where we boot from NetBoot, but we update the file system on the clients local drives.

Also, due to the limitations of number concurrent Apple File Protocol [AFP] connections using Mac OS X 10.6.x (and others) client's File Sharing. If you need to NetBoot more than 10 clients and run maintenance utilities, you can't use a network shadow file, because after the tenth client connecting, it will either try to use a local disk for the shadow file or not NetBoot properly.

[Sean_Ginn]

Can you run disk utility/disk repair on the drive?

[chutiya]

no. Can run a "verify" but nothing that requires the disk to unmount. Its almost like it thinks its booted in disked mode and not diskless.

[jwojda · Accepted solution]

see this - https://jamfnation.jamfsoftware.com/discussion.html?id=5416 - It talks about 10.6, but I've used it on 10.7 and 10.8... and since I'm seeing it in 10.9's, I'm starting to move the file into there -

In certain, situations you never want use a clients local disk for the NetBoot shadow file, like if you want to run hard disk utilities like Disk Utility or Disk Warrior, or for us if we want to run the file system maintenance software we use, radmind, out-of-context. Where we boot from NetBoot, but we update the file system on the clients local drives.

Also, due to the limitations of number concurrent Apple File Protocol [AFP] connections using Mac OS X 10.6.x (and others) client's File Sharing. If you need to NetBoot more than 10 clients and run maintenance utilities, you can't use a network shadow file, because after the tenth client connecting, it will either try to use a local disk for the shadow file or not NetBoot properly.

[chutiya]

just before I do this. I dont need to type all that out from the here (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) do I? Just download the file and replace it?

thanks,

[jwojda · Accepted solution]

sorry, yes I just downloaded the rc.netboot file, open up the netboot.dmg file and rename the original rc.netboot and put the new one in.

[chutiya]

thanks jwojda - will give this a whirl and let you know how I get along.

[chriscollins]

Did you disable the spotlight daemons on your net boot source image? Whenever I forget to do that before making it, I have this same problem since spotlight starts to try to index the local hard drive.

[Sean_Ginn]

If none of that works, try booting into the HD recovery partition and then from there net boot. That should make sure that the HD isn't is use anywhere and allow you to unmount the drive.

[dlondon]

Hi,

Whilst I've heard great success stories using RAM Disks from that info from Utah, it doesn't really solve the problem of why Diskless is not working. I've given some info in https://jamfnation.jamfsoftware.com/discussion.html?id=8569 on how to see what is going on with the AFP mount which looks to be a critical piece. No AFP Mount = no diskless mode

Perhaps you can check those things and tell us if the issue is consistent or sometimes works?

Regards,

David

[chutiya]

thank you all. I'm going to try the suggestions and report back by end of week. All help greatly appreciated.

[michaelhusar]

here what I do for my net boot image (now Mavericks 9.1)- hope it helps:

*) sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.metadata.mds.plist to stop spotlight
*) turn of WIFI
*) sudo pmset -a hibernatemode 0 (thanx to jamf-acticle 7091)
*) after testing I do also use composer to "shrink" to a .dmg
*) then the System Image Utility
*) after that I just check whether the dmg in the .nbi has about 1GB to "breathe" - adjust as above with sudo hdiutil resize -size 10g /path/to/NetBoot/yourImageName.nbi/NetBoot.dmg
*) then I change the /etc/rc.netboot to that of 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 *) then I upload to our NETSUS version 2.0

[chutiya]

@jwodja

thank you for the tip - it worked brilliantly.

Just a quick bit to add however. The downloaded file is named rc.netboot.sh - anyone that is trying this, you need to do a get info and take the .sh out and ask it to use .netboot as the file extension.

apart from that top tip.

thank you VERY much.

[kalikkalik]

http://support.apple.com/kb/TS4316?viewlocale=en_US&locale=en_US

[kevinmwhite]

Thanks for that lead kilikkalik! That Apple Support Article should also be marked as "Solved"!

In my latest case it turns out the default service ACLs for the netboot# users were not allowed File Sharing access. Thus, they could not write shadow files back to the NetBootClients share. Dumb bug.

[kalikkalik]

Kevin,

No problem - we've run into that a few times now...and times when the netboot/shadow file garbage does not work, it has.

- jeremy matthews (hereby known as kalikkalik because there is no way to change my tricking nickname)

[ChrisSVCarter]

Kevin/Jeremy,

I'm trying to do the fix as per the Apple Support Article but I don't seem to have any netboot users (netboot100, netboot101 etc.) so can't do the ACL bit. My image netboots fine but is stubbornly refusing to be diskless. Server is running 10.9.2 if that's relevant.

What am I doing wrong?

[kevinmwhite]

ChrisSVCarter,

Sorry for the delay, I didn't notice your response until just now.

By default the Server.app hides the netboot# accounts as these accounts are considered "System Accounts." In Server.app simply choose View > Show System Accounts. Also if you have any other directory services configured for this sever, make sure that you have the "Local Accounts" selected at the top of the User list.

Good Luck,
Kevin

[ChrisSVCarter]

Hi Kevin,

Thanks for the response. I've done Show System Accounts and I can see a raft of other local users and system users, but no Netboot users. There's NetBIOS, Network Services and Network Statistics Daemon, but that's it for users starting with 'Net'.

The RAM based solution with rc.netboot seems to be working for us now, but it would be nicer to have the less 'fudge' like method working if we could.

Cheers,

Chris

[winningham_2]

Are any of you guys net booting from JAMF's NetBoot/NetSUS 3 and seeing this?

[winningham_2]

Here is how I fixed my issue...
1) Within my Netboot.nbi directory, I navigated to my NBImageInfo.plist and looked for <key>SupportsDiskless</key>. 2) Using your favorite editor (TextWrangler.app or nano for me), edit that key's value from <false/> to <true/> and save. 3) My changes look like the below:
<key>SupportsDiskless</key> <true/>

Now when I launch Casper Imaging, I am able to let auto run/prestage take off without having issues unmounting the target HD (Macintosh HD).

Does this happen to work for any of you?

[Buscher]

+1 Jermemy, I've been battling this since I updated my server to 10.9. I had to first update my images but when I was still having trouble. The server Reset is what it needed.

Replacing the rc.netboot file as found in other posts did nothing for me but produce a black screen.

[kalikkalik]

Buscher- glad it worked!

Thanks,
jeremy

[bentoms]

Hi all,

Just wanted to add that I created a tool to help with NBI creation, so if you get the chance please give it a go.

It forces diskless but if you're still having issues you can also install a modified rc.netboot file. (All included in the app).

https://jamfnation.jamfsoftware.com/discussion.html?id=11356