ConfigMgr 2007 : PXE Cache Behavior

November 16, 2010 at 9:02 am in ConfigMgr, ConfigMgr 2007, ConfigMgr 2007 R2, ConfigMgr SP2, configmgr2007, ConfigMgr2007 R3, Deployment, OSD, PXE, R3, sccm, SCCM 2007, SCCM 2007 R2, SCCM 2007 R3, SCCM 2007 SP2, sccm2007 by Kenny Buntinx [MVP]

Config Mgr OS deployments when using PXE boot , you’ve probably had machines that did not want to boot the task sequence as it stated “No task sequence found, booting onto the hard drive”.

This is most likely due to a previous task sequence being advertised to that machine. By default ConfigMgr will cache the PXE advertisement for 60 minutes (Default setting) and then it will expire. Most of the time you can speed up things when restarting the WDS services. Restarting the WDS services ( clearing the cache) isn’t the best solution. In ConfigMgr SP2 the cache expiry can be set in the registry.

  • On an x86 machine the located under:
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SMS\PXE
  • On an x64 machine the registry key is under:
    HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\SMS\PXE

Create a new DWORD value CacheExpire, and set the desired value in seconds. For example, if you prefer the cache expired in 2 minutes, set the value to 120. If the value is set to 0, then the default 60 minutes value is used.

Note: Setting the value in CacheExpire is only supported in ConfigMgr 2007 SP2.

Be careful if you have R2 installed and unknown computer support enabled because if you set the cache expire value too low and you are using a mandatory task sequence your machine will continuously start the same task sequence every time it reboots.

 

Hope it Helps ,

Kenny Buntinx

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