Help me understand the workstation pxe boot/boot.wim process

[92 5 oh]

Hey everyone, I'm hoping someone might be able to shed some light on the whole pxe boot process. I don't completely understand how it works and now we are having an issue with our workstations not pulling an image. It would certainly be in my best interest to understand all this. We are running SCCM 2012 R2 and only use it for imaging workstations and servers via pxe, for now.

 

Here's what's going on, we pxe boot a device, it grabs the boot.wim file and downloads it successfully. After it's downloaded WinPE starts loading (we can see our custom background), and the task sequence is supposed show up but the device reboots after about 30 seconds. When I press F8 and check for an IP I do not have one, it actually doesn't see any adapters so I'm guessing the drivers aren't installed, or the wim file is corrupted.

 

Further investigation....In Config Manager we only have the two default boot images (x86 and x64). When I import new boot and storage drivers I've only added them to these boot images, and both boot images are set to "deploy this boot image from the PXE-enabled distribution point". These two boot images are shared out of "\\server.domain.com\sms_cwy\osd\boot\i386\boot.wim" and "\\server.domain.com\sms_cwy\osd\boot\x64\boot.wim" , respectively.

 

All of our task sequences are set to use the x64 boot image. It's also my understanding that a device will grab whatever boot image was last used, regardless of what is set in the task sequence. Is this correct?

 

While a workstation was downloading the boot image I noticed that the download path was \SMSImages\cwy00005\boot.cwy00005.wim. So I found this path on the server is actually "\\server.domain.com\REMINST\SMSImages\CWY00005\boot.cwy00005.wim" which is part of RemoteInstall folder and think was created when WDS was installed.

 

And this is where my confusion sets in. I have no idea how/why this boot image was created, and why it's being used by the workstation. I'm not sure why the workstation "decided" to use this path to pull the boot image. I think at one time I heard one of our network engineers mention there's a helper address in the router that points pxe requests to the SCCM server, but I could have misunderstood. Maybe this helper could reference the download path?

 

Since I've only ever updated the two default boot images I'm guessing that's why pxe is failing, this boot.cwy00005.wim image doesn't have the drivers loaded. But what I find strange is the default x64 boot image has an Image ID of cwy00005, which is referenced in this "rogue" boot image. Why?

 

I believe if I could get the devices to pull the boot image from the default location (server.domain.com\sms_cwy\osd\boot\x64) they would work as expected. But I'm not sure how to do that. I'm not sure why this is broken now, it was working a few days ago and there haven't been any changes that I'm aware of.

 

Any help would be greatly appreciated.

[anyweb]

that's a long post but to simplify things, you probably just need to add drivers for the network card for the hardware you are PXE booting, to the boot image you use in your task sequence,

 

once you've done that, and then re-distrbuted the boot image to all distribution points, try pxe booting again, does it work, or fail ?

[92 5 oh]

Thanks for the feedback anyweb,

It seems that a Dell Deployment ToolKit was installed, for the servers. I believe this messed with the boot image. I ended up rolling back to a snapshot before the DTK was installed and the OSD is coming up now. I tried a task sequence but it failed. I *think* I know why though. I'll report back after some testing.