Win PE & Physical Drive Enumeration
Hello..
I’ve been looking at an issue for the last couple of days that has me somewhat confused. I know there have been other posts regarding this but I’ve not yet seen a definitive reason behind it…unless I have missed it all togehter..
We have a small number of systems in the environment that have two physical drives for example a 75GB drive and a 300GB drive, meaning the preferred setup would be:
Disk 0 (75GB)
200 MB: System reserved (bitlocker): Hidden Partition
50GB: OSDisk: C Partition
24GB: Data: D Partition
Disk 1 (300GB)
300GB: Extra: E Partition
Can someone please explain why in Win PE these disks randomly swap between Disk 0 and Disk 1??
I need to ensure that in a system refresh scenario these desktops only ever have W7 Enterprise installed to Disk 0 (in the example above) thus leaving Disk 1 alone.
We are using the OSPart task sequence variable at the apply OS Phase so I am going to try to use the following script that I believe Niall had a hand in creating in order to target the current partition that has Windows installed:
<job id="GetDriveletter">
<script language="VBScript" src="..\ZTIUtility.vbs"/>
<script language="VBScript">
dim driveSearch
Set objFSO = CreateObject("Scripting.FileSystemObject")
Set colDrives = objFSO.Drives
For Each objDrive in colDrives
driveSearch = objDrive.DriveLetter & ":\\Windows\\explorer.exe"
strComputer = "."
Set objWMIService = GetObject("winmgmts:" _
& "{impersonationLevel=impersonate}!\\" & strComputer & "\root\cimv2")
Set colFiles = _
objWMIService.ExecQuery("Select * From CIM_DataFile Where Name = '" & driveSearch & "'")
If colFiles.Count < 1 Then
Else
oEnvironment.Item("OSPART") = objDrive.DriveLetter & ":"
End If
Next
</script>
</job>
I would still very much appreciate any insight as to why the Disk numbers change at what seems to be random intervals….is it a hardware issue i.e. symptom of using SATA drives, or that OSD prefers the larger drive, or just a Win PE quirk...
Thanks.
Rich.
October 27th, 2011 10:55am
Most likely just a WinPE quirk
/ JohanRegards / Johan Arwidmark Twitter: @jarwidmark Blog: http://www.deploymentresearch.com FB: www.facebook.com/deploymentresearch
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October 31st, 2011 8:25am
Yes, concur with Johan.
As I know when load into WinPE, disks marked from disk0 to diskN in the order in which they are enumerated.Therefore, the disk-assignment numbers may change between startups.
So I think Niall's script is the best solution.
Take a reference of the following links, and they seem to explain the reason:
http://support.microsoft.com/kb/937251
http://support.microsoft.com/kb/825668
Hope this will help.
Thanks
November 3rd, 2011 5:26am