Disk Management is showing multiple disks after adding VNX LUN.

Question

I recently zoned and attached a host to our VNX, configured a test LUN, and attached the host. I did a rescan on the disk within disk management, and multiple disks showed up. I'm using MPIO and setting it up with the DGC VMX product ID. 

Answer 1

Hi @Diaz, Javier,

Thank you for reaching out to Microsoft Q&A forum!

It seems like you’re encountering an issue with multiple disks showing up in Disk Management after configuring a test LUN on your VNX storage system and using MPIO. Let’s troubleshoot this situation.

Check LUN Configuration:

• Ensure that the LUN configuration on your VNX is correct. Verify that the LUNs are properly mapped to the host and that the host ID is set appropriately.
  • If you’re using a DGC VMX product ID, make sure that the LUNs are correctly associated with the host.
  Host ID and LUNZ:

  - The issue you’re facing might be related to the LUNZ paths. LUNZ is a special path that indicates a LUN with a host ID of 0. It’s typically used to prevent the array from sending LUNZ paths to the host.
  
     - In your Storage Group for the hosts, consider adding a small LUN with the HLU (Host LUN ID) set to 0. [This will prevent the array from sending LUNZ paths to your server](https://www.dell.com/community/en/conversations/vnx/server-2012-mpio-problems-no-powerpath/647f5220f4ccf8a8deb402ae)[1](https://www.dell.com/community/en/conversations/vnx/server-2012-mpio-problems-no-powerpath/647f5220f4ccf8a8deb402ae).
  
        - Name this LUN something like “DONOT REMOVE LUNZ” to avoid accidental removal.
  
        **Reboot the Host**:
  
           - After making any changes to the LUN configuration or adding the LUN with HLU 0, reboot the host. [Sometimes, Windows Server 2012 R2 behaves better with MPIO after a reboot](https://www.dell.com/community/en/conversations/vnx/server-2012-mpio-problems-no-powerpath/647f5220f4ccf8a8deb402ae)[1](https://www.dell.com/community/en/conversations/vnx/server-2012-mpio-problems-no-powerpath/647f5220f4ccf8a8deb402ae).
  
           **Verify MPIO Installation**:
  
              - Confirm that you’ve installed MPIO services correctly on your Windows Server 2012 system.
  
                 - If you haven’t already, install MPIO services and then reboot the server.
  
                 **Disk Management**:
  
                    - In Disk Management, you might see multiple disks (some offline) due to incorrect configurations or conflicting paths.
  
                       - The 2TB partition you mentioned could be related to MBR (Master Boot Record) limitations. MBR supports up to 2TB partitions, and GPT (GUID Partition Table) is recommended for larger disks.
  
                          - The “GPT Protective Partition” likely indicates that the disk was previously formatted with GPT.
  
                          **PowerPath (Optional)**:
  
                             - While you mentioned not having PowerPath, consider installing it if you continue to face issues. PowerPath is an EMC multipath solution that provides additional features and better control over paths.
  
                                - However, MPIO should work without PowerPath, so let’s focus on the other steps first.
  

Remember to document any changes you make and proceed cautiously.

Best regards,