Cant Netboot: tftp "error code 512: Access violation" on fresh install

Question

Cant Netboot: tftp "error code 512: Access violation" on fresh install

Hey everyone,

Im trying to netboot clients from my mac server running on a late model mac mini. Eventually I want to be doing this with the Deploy Studio software package

On a completely fresh install of Mountail Lion with Mountain Lion Server I have been using the documentation provided on the DS website set up the Mac Server, and installed and run Deploy Studio Assistant to create a netboot set.

To put it shortly at this point it won't netboot as it should. With the netinstall service running on the server, the first red flag is that when selecting the startup disk on the client mac, the netboot image doesnt show up. Even if I set the startup using the bless command it wont boot from the network. After examing the logs on the server I can see that the server is acknowledging the bsdp requests and returning a list. This exchange reccurs for a number of repeats and then the exchange ends abruptly and the client boots to the local OS. Running through some of the troubleshooting information on the internet I was led to test the tftp connection. From the client I ran tftp to the ip of the server and attempted executing get /Library/Netboot/.../booter. This returns "Error code 512: Access Violation."

My instinct and the apparent instinct of the internet is that this is a permissions problem. So to correct this, starting with the file 'booter' and working my way up the folder tree, set gradually higher levels of permissions until now I am at the point where permissions is 777 all the way up to the folder tree, and I am continuing to get the same error.

Next, thinking that maybe this is really some oddball network issue related to my org that I dont understand, I set up a private network with just my machine and a client, enabling dhcp from the mac. Even this got me the Error Code 512: Access Violation message when running the tftp test, and just in case I also just went ahead and tried to netboot it and got the same conversation in the log.

In the process of doing this I changed about every setting I could think to change including jacking around with the tftp.plist and got nowhere. So I have now started with a totally fresh install again and leaving deploy studio out of the picture created a netboot set from the mountain lion installer and again with a completely fresh install I'm having exactly the same issue with netbooting, and when I test the tftp connection I get the same "Error Code 512: Access violation"

Anyone have any ideas?

Mac mini, OS X Mountain Lion (10.8)

Posted on Jan 29, 2013 1:32 PM

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Answer 1

Jul 3, 2017 12:52 AM in response to Brian Nesse

FWIW: found this while struggling with 10.11 Server (i.e. Server 5.0.15). Using TCPDump I could see we were getting an "access violation" reply from our attempts to do tftp.

Seeing as tftpd accesses the nbi folder via a symlink (thanks, Brian) I wondered: can it just not hack them being on a separate volume?

And moving them to the boot disk worked. But then, moving them to another internal drive worked too, so ignore that theory. I think something was up with the permissions on some part of the /Volumes/Volname/Libarary/Netboot/NetBootSP0/ path.

My actual conclusion: try deleting and remaking the netboot folder on your volume. If that doesn't work and the images AREN'T on your boot drive, try the boot drive. Me, I'm sticking with the boot drive, I'm not using any big netboot images.

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Answer 2

Jul 7, 2017 8:08 AM in response to Piers Goodhew

FWIW, my images are *never* located on the boot volume.

The reality is that, many times, failure to serve up images properly is just because something didn't start up properly. Toggling the NetInstall service off, and back on, should always be the first step when troubleshooting.

The next level is to completely tear down the configuration (i.e. disable all share points), and set it up again from scratch.

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Answer 3

Jan 30, 2013 8:04 AM in response to wolverinetheanml

Did you enable tftpd in "insecure" mode?

man tftpd

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Answer 4

Jan 30, 2013 12:23 PM in response to Brian Nesse

Thanks for your response, Brian.

tftp looks to be running in insecure mode. Which my understanding is what its supposed to be. Below is a copy of my tftp.plist:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/Pr\

opertyList-1.0.dtd">

<dict>

<key>Disabled</key>

<true/>

<key>Label</key>

<string>com.apple.tftpd</string>

<key>ProgramArguments</key>

<array>

<string>/usr/libexec/tftpd</string>

<string>/private/tftpboot</string>

</array>

<key>inetdCompatibility</key>

<dict>

<true/>

</dict>

<key>InitGroups</key>

<true/>

<key>Sockets</key>

<dict>

<key>Listeners</key>

<dict>

<key>SockServiceName</key>

<key>SockType</key>

<string>dgram</string>

</dict>

</plist>

I was wondering if deploy studio may have caused the problem so after a clean wipe I left out installing deploy studio and created a nbi off the install program, and set up netboot with that and I'm continuing to get the same Error code 512 along with the other symptoms.

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Answer 5

Jan 31, 2013 8:04 AM in response to wolverinetheanml

Yep, that's configured for insecure mode.

Another test is to look in /private/tftpboot/NetBoot.

There should be a link in there. Make sure it points to a valid volume containing a /Library/NetBoot/NetBootSP0

Did you enable verbose mode when you tested? Also, did you have spaces in the nbi name? As I recall the tftp command line doesn't like that much.

bnesse5:~ brian$ tftp bnesse6

tftp> verbose

Verbose mode on.

tftp> get NetBoot/NetBootSP0/NetBoot_DS_Test.nbi/i386/booter

getting from bnesse6.apple.com:NetBoot/NetBootSP0/NetBoot_DS_Test.nbi/i386/booter to booter

Received 313526 bytes in 2.6 seconds 964695 bits/sec

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