ConfigMgr 2012 – Where’s my PXE CacheExpire gone!?

In ConfigMgr 2007 we had a registry key called CacheExpire which would allow a client to start a new PXE session after 60 minutes. The idea is, if a build is mandatory the cache will hold onto the session to ensure it doesn’t get into a rebuild loop.

It was a bit of a pain when you were developing/testing your OSD builds because if it failed, you had to wait for the cache to run out or clear it manually. So many engineers would change the key to 120 seconds or so.

HKLMSoftwareMicrosoftSMSPXE CacheExpire=120

I’ve recently been testing a new build in ConfigMgr 2012 using PXE as my boot method, and went in search of the CacheExpire value to speed up the process, and found its no longer there. In fact, the entire PXE key is missing.

The reason is quite simple, in ConfigMgr 2012 the PXE Service Point is no longer a separate role – it’s now integrated with the Distribution Point role. So I checked in the DP registry key for a CacheExpire… no luck.

HKLMSoftwareMicrosoftSMSDP

So I decided to try and create one and see how it went… bingo, my PXE Cache is now 120 seconds.

Fox the lazy, here’s the exported key & value

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINESOFTWAREMicrosoftSMSDP]
"CacheExpire"="120"

Matt Shadbolt