I am in the midst of migrating to a Hyper-V 2012 R2 cluster and am currently configuring the first host to connect to the iSCSI CSV via MPIO.

I "think" I have everything working properly but when I try to create a log file to verify via the MPIO properties (GUI) or invoke the "mpclaim -v" powershell command (or command prompt) while elevated as Admin, I get the following errors;

GUI - Failed to probe MPIO storage configuration. Access is denied.

Elevated Powershell/CMD - File creation failed. C:\Windows\System32\MPIO_Configuration.log. Error 5 Failed to write MPIO configuration to file. Access is denied.

I have only been able to locate one article relating to the same problem but the solution was not applicable to me. Someone made a reference to " Local Security Policy/Public Key Policies/Encrypting File System/Properties/Certificates" and to allow something there but when I go there on the local machine, there are no keys or anything.. just a message that says "No Encrypting File System Policies Defined".

Here's the article;


Anyone have any insight into this?

Thank you in advance!

  • Do you have any authentication requirements set on the SAN? CHAP or limited by IP? – pxed Jan 23 '15 at 19:31
  • no authentication is configured – Steven Gedzyk Jan 23 '15 at 20:55
  • I'm having the same problem on 2008 r2 – Pete May 1 '15 at 21:27
  • > I'm having the same problem on 2008 r2. This problem is kinda "known issue" so I assume there is solution into database articles. – Net Runner May 2 '17 at 11:29

solution is (if you dont want to troubleshoot EFS certificates), create a small temporary VHD, attach it, format to FAT32 and you can save MPIO report there. ThIS is valid also for mpclaim -v (access denied issue).

  • 1
    I would recommend you to add commands next to the explanation so it's a better formed answer and can be easier to follow :) – sysfiend May 11 '16 at 11:48

I used a USB thumb drive formatted as ExFAT and that worked as well. MPIO settings copied right over.

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