client records and multiple PXE boots

[vk5pj]

Hi,

during the re-build of our reference image for win 7 and the start of a reference image for Win 8.1 under SCCM 2012 I have noticed that after two or three builds, the records for the client PC's no longer work.

 

In the logs on each of my test PC's I can see reported the error of "no task sequence can be found for this computer" yet only 30 minutes before hand they were happily building via the same TS.

 

When it occurs, the boot goes through to the stage where it says "preparing network settings" then at this point it reboots.

 

 

One is a physical PC and two are esx VM's. I have used these platforms many times before when on SCCM 2007 and never had a hitch but notice that in SCCM 2012 this has become a common thing for us. It would seem that the only way to get them working again is wait two days (over a weekend worked) between builds or delete the record for each computer and then generate them again after waiting for SCCM to delete them entirely.

 

I am hoping this is a silly configuration mistake we have made or others may have an insight into what might be wrong.

 

regards,

 

vk5pj (Peter)

[vk5pj]

Hi,

further to my original post, I have found that I can seemingly do as many PXE boots as I like if the TS never gets to the point where the SCCM client is installed and allowed to communicate back to the SCCM server. I found this yesterday when trying to get another TS to run, I had many failures in the early part of the TS where it crashed and burned before the SCCM client step. I was able to keep using one PC and its client record for over 10 boots but after I had found my error and had gotten past the point where the SCCM client initialised, the next PXE boot was then again exiting early :angry:.

 

So it would seem that on a non domain joined machine, when the client initialises it makes a change to the client record in SCCM that triggers this fault. At this point I have no idea what this change might be, I do know if I delete the client record in SCCM and then recreate it after a while it will all work again.

 

Regards, vk5pj (peter)

[Rocket Man]

A known computer should not PXE boot to a task sequence if the PXE flag has been set initially.

 

If using unknown computer support for the 1st time the PXE flag will not get set and also the available task sequence which was used to image the unknown computer will also not be available anymore considering the system is now known (it has an entry in the CMDB). If you delete the system from SCCM it is unknown again and will (should) pull down any task sequence targeted at the unknown computer collection.

 

If you are importing computer information (which I think is the method you are using) and not using unknown computer support then to get the machines to image again via the PXE method is to clear the PXE flag on the required system(s). i:e right click on collection or individual system and select clear PXE flag.

 

Maybe you already know about this, but if not then this maybe your solution..

[vk5pj]

Hi Rocketman,

your mention of the PXE flag sparked a thought, for some unknown reason the PXE flag is never being set on a computer record. When I go to clear the PXE flag (usually in a fit of anger) I find it has never been set. This may be a part of my overall problem, I think that WDS is responsible for keeping a track of the PXE boots so might have to poke around there on a quiet day.

 

We are not using "unknown computer support" we manually register new computers via NetbiosName and MAC, it would seem I have to keep digging.

 

Regards,

Peter

[vincelewin]

I use unknown with a password.

 

You can then take a new machine out of a box and boot it directly from NIC the only time you need to interveen and delete the object in SCCM, as Rocket Man said, is if you want to re-deploy a machine or if a fault occurs during the task sequence after the object has been created.

 

I have never seen that PXE flag set dont know what thats for or need to reset it!

 

Regards

 

Vince

[Rocket Man]

 

I have never seen that PXE flag set dont know what thats for or need to reset it!

 

 

Hi Vince

The PXE flag is actually quite useful in deployment scenarios, actually very useful. When you first image your unknown machine it wont be set as previously mentioned.

However when you get all your systems into desired collections you can deploy a task sequence as required via PXE to a collection if you are refreshing them. Once the systems get's this deployment it will set a PXE flag.

 

Now here is the beauty of this. You can set your Task sequence deployment to only deploy via PXE and boot media (if of course on 2012 SP1 atleast) and to always rerun. This means that this task sequence will always rerun on the collection, but only via PXE or boot media. So no-more creating new Task sequences and re-deploying. Whenever you need to refresh your systems that have the PXE flag already set from the initial required deployment just simply clear the flag and press f12 and watch it re-image.

 

On the other-hand when the PXE flag is set and a user accidentally presses f12 on a machine it will not PXE boot because of the flag being set even though the deployment is set to always re-run but only to media and PXE.

 

PXE flag is a pretty cool and important part of SCCM and once understood and used correctly it will mean less time creating and re-deploying of task sequences, and now with 2012 SP1+ with the new deployment options i:e only PXE and boot media makes it even better and more valuable!