Author: rlevchenko

Windows 2012 R2 RTM and Windows 8.1 RTM are available to download

Starting today, we will extend availability of our current Windows 8.1, Windows 8.1 Pro and Windows Server 2012 R2 RTM builds to the developer and IT professional communities via MSDN and TechNet subscriptions. The Windows 8.1 RTM Enterprise edition will be available through MSDN and TechNet for businesses later this month

 

Fix: Can’t re-install MPIO feature on Server 2012/Failed MPIO cluster test

During cluster verification you can receive the following message:

Validate Microsoft-based MPIO disks – Failed

Image

The main reason is that you have nodes with different MPIO driver version.

QFE Number is not the same on every nodes.

mpio

If you check driver properties (use device manager) you can verify this QFE

Image

QFE version depends on OS patch level (installed SP , hotfixes or updates). In my case, I have the same patch level on every nodes. So , I decided to re-install mpio feature on every nodes (remove-windowsfeature). After succesfull uninstallation and server restart I couldn’t get MPIO back because of “ The request to add or remove features on the specified server failed. Installation of one or more roles,role services, or features failed. Error:0x800f0922″ . mpio ps error

Install-WindowsFeature uses DISM utility and has the same log files for troubleshooting. They are located in %systemroot%\Logs\DISM and %systemroot%\Logs\CBS. In logs I found some interesting strings:

“The device instance cannot be created because it already exists”

“ROOT\MPIO001”

mpiologs

NICE! I understood that Install-WindowsFeature couldn’t delete this key and create some new ones. So, resolution is DELETE ROOT\MPIO and re-run Install-WindowsFeature. EASY AS PIE !? regedit.exe ->  HKLM:\System\ControlSet001\Enum\MPIO -> right click -> delete  = failure!mpioregedit

Of course, you cannot just delete these keys. I would recommend PSTools by Mark Russinovich (PSExec tool). This tool is able to enable  “GOD MODE” for your registry :).

Use carefully!

Set-Location c:\PsTools
.\psexec.exe -i -d -s c:\windows\regedit.exe

deleteregmpio

That’s all! Problem has gone away!