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Powershell to find mpio path state and if its using alua RRS feed

  • Question

  • Hello,

    With powershell I can get the mpio disk instances and number of paths.

    I can't seem to get any information to show up for path state or alua.

    PS C:\> gwmi -Namespace root\wmi -Class mpio_dsm_path -list


       NameSpace: ROOT\wmi

    Name                                Methods              Properties
    ----                                -------              ----------
    MPIO_DSM_Path                       {}                   {DsmPathId, PathWeight, PrimaryPath, Reserved}

    PS C:\> gwmi -Namespace root\wmi -Class mpio_dsm_path_v2 -list


       NameSpace: ROOT\wmi

    Name                                Methods              Properties
    ----                                -------              ----------
    MPIO_DSM_Path_V2                    {}                   {ALUASupport, DsmPathId, FailedPath, OptimizedPath...}

    PS C:\> (gwmi -Namespace root\wmi -Class mpio_dsm_path_v2).failedpath
    PS C:\>

    does not list anything. Any help would be appreciated.

    Saturday, August 4, 2012 8:33 PM

Answers

  • Hi ,

    It appears there are no WMI objects in that class you are a calling.

    The –list parameter will show the class definition, even if no objects are found.
    You can type the following command and no result returned.
    gwmi -Namespace root\wmi -Class mpio_dsm_path_v2

    There is no class objects have been found in that namespace. Meaning any subsequent calls for sub properties (like .failedpath) will return null.


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Monday, August 13, 2012 4:21 AM

All replies

  • I know nothing about this WMI class or drivers in general, but I see in http://msdn.microsoft.com/en-us/library/windows/hardware/ff562388(v=vs.85).aspx that Windows creates the class but doesn't really fill it with data.  Apparently you need something in your OS that will fill it out.  I guess your PC doesn't have this other part.

    Jose R. MCP
    Code Samples

    Saturday, August 4, 2012 11:12 PM
  • Hi webJose,

    thanks for this pointer which starts out:

    MPIO publishes the MPIO_DSM_Path_V2 WMI class but expects the DSM to register the GUID and handle its implementation. An MPIO driver uses the MPIO_DSM_Path_V2 WMI class to identify the path ID as reported by a DSM.

    I am using MSDSM (microsoft device specific module) to handle my pathing. I wonder if I have to query both at the same time?

    (I currently have 4 paths, 2 optimized, 2 non-optimized)

    Any suggestions would be appreciated.

    Monday, August 6, 2012 9:01 PM
  • Hi,

    Please try below code:

    (gwmi -Namespace root\wmi -Class mpio_dsm_path_v2).failedpath.value

    or

    gwmi -Namespace root\wmi -Class mpio_dsm_path_v2 |select-object failedpath

    In this issue, we should fist check all properties and methods for it:

    gwmi -Namespace root\wmi -Class mpio_dsm_path_v2 |get-member

    Regards

    Yan Li

     

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    Yan Li

    TechNet Community Support

    Tuesday, August 7, 2012 2:39 AM
    Moderator
  • Hi Yan Li,

    Thank you for your assistance, but I did not get any value for failedpath. (or other properties)


    PS C:\Users\Administrator> (gwmi -Namespace root\wmi -Class mpio_dsm_path_v2).failedpath.value
    PS C:\Users\Administrator>

    I can get this info:

    PS C:\Users\Administrator> (gwmi -Namespace root\wmi -Class mpio_disk_info).driveinfo | % {Write-host "Name: $($_.name) Paths: $($_.numberpaths)"}
    Name: MPIO Disk0 Paths: 4
    Name: MPIO Disk1 Paths: 4
    Name: MPIO Disk2 Paths: 4
    Name: MPIO Disk3 Paths: 4
    Name: MPIO Disk4 Paths: 4
    Name: MPIO Disk5 Paths: 4
    Name: MPIO Disk6 Paths: 4
    Name: MPIO Disk7 Paths: 4
    Name: MPIO Disk8 Paths: 4

    Now I need to add the additional information which appears the dsm_v2 class maybe holding.

    thanks


    Tuesday, August 7, 2012 9:32 PM
  • Hi ,

    Is this ps helpful to retrieve the info?

    PS C:\Users\Administrator> (gwmi -Namespace root\wmi -Class MPIO_PATH_INFORMATION).Pathlist

    Thanks.


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Friday, August 10, 2012 10:57 AM
  • Hi ,

    It appears there are no WMI objects in that class you are a calling.

    The –list parameter will show the class definition, even if no objects are found.
    You can type the following command and no result returned.
    gwmi -Namespace root\wmi -Class mpio_dsm_path_v2

    There is no class objects have been found in that namespace. Meaning any subsequent calls for sub properties (like .failedpath) will return null.


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Monday, August 13, 2012 4:21 AM
  • I know this is an old thread but, since I didn't see an answer, I thought I would post it here.

    You can query the DSM_QueryLBPolicy_V2 WMI class.  That will return a DSM_Load_Balance_Policy_V2 LoadBalancePolicy class. That provides an array of MPIO_DSM_Path_V2 classes.  There you can find the path state information you're looking for.

    • Proposed as answer by BT Mike Friday, February 5, 2016 6:41 PM
    Friday, February 5, 2016 6:40 PM