Performance Tuning Guidelines for Windows Server 2008 R2 mistake?


  • Hi all,

    I'm reading the "Performance Tuning Guidelines for Windows Server 2008 R2" and I think there is same kind of error. At page 53 there is a sub chapter "I/O Priorities" that explain how to handle I/O priorities.

    In the guide it is said that in the registry I have to have a key:

    HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\DeviceClasses\{Device GUID}\DeviceParameters\Classpnp\

    Where {Device GUID} I think it is the value I get in device manager under one of my disks -> properties -> details -> "Device Class GUID"

    the trouble is that under the key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\DeviceClasses\ I've no subkey matching my disk's device class guid! Maybe I'm drunk but I've checked every sub key under HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\DeviceClasses\ but neither of them as a subkey named "DeviceParameter"!!

    So am I wrong? 

    Thursday, April 3, 2014 1:09 PM


  • Hi Andrea,

    To find the "DeviceParameter", please try to follow the steps below:

    1.Find this registry key and note the DeviceInstance value:
    2.Find the device instance registry key under "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum" which contains information about the devices on the system and get the device interface GUID:
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\USB\<hardware id>\<instance id>\Device Parameters

    I hope this helps.

    Sunday, April 6, 2014 9:43 AM