Sign in
 
HomeWindows 8Windows 7Windows VistaWindows XPMDOPWindows IntuneLibraryForums
Windows Client >
> 
> 
Why can't we see volume mount point for an EFI System partition

Domanda Why can't we see volume mount point for an EFI System partition

  • Tuesday, February 12, 2013 5:49 AM
     
     
    Sign In to Vote
    0

    Hi,

    On listing volume using diskpart.exe, I can see the EFI System partition as a volume.

    DISKPART> list vol
      Volume ###  Ltr  Label        Fs     Type        Size     Status     Info
      ----------  ---  -----------  -----  ----------  -------  ---------  --------
      Volume 0     D                       DVD-ROM         0 B  No Media
      Volume 1     C                NTFS   Partition     49 GB  Healthy    Boot
    * Volume 2                      FAT32  Partition    100 MB  Healthy    System

    But on using mountvol.exe, I don't see the mount point associated to the EFI System partition.

    Mountvol.exe
    Possible values for VolumeName along with current mount points are:

        \\?\Volume{bdb58d69-1f3a-46d6-95e0-2976e82b7b0e}\
            C:\
        \\?\Volume{04912715-73a1-11e1-8354-806e6f6e6963}\
            A:\
        \\?\Volume{04912714-73a1-11e1-8354-806e6f6e6963}\
            D:\

    After I assign a drive letter to the EFI System partition and used mountvol.exe it showed, "The EFI System Partition is mounted at E:\ ", but no mount point for the volume.

        \\?\Volume{bdb58d69-1f3a-46d6-95e0-2976e82b7b0e}\
            C:\
        \\?\Volume{04912715-73a1-11e1-8354-806e6f6e6963}\
            A:\
        \\?\Volume{04912714-73a1-11e1-8354-806e6f6e6963}\
            D:\
        The EFI System Partition is mounted at E:\

    Does EFI System partition has no volume associated to it? if so then why Diskpart shows it as a volume?

     

All Replies

  • Tuesday, February 12, 2013 3:58 PM
     
     
    Sign In to Vote
    0

    I would venture that this is a by design behavior since there isn't any good reason to mount/unmount an EFI partition.

     
  • Wednesday, February 13, 2013 12:20 PM
     
     
    Sign In to Vote
    0

    Hi Imperfect1,

    I agree with your point, "there isn't any good reason to mount/unmount an EFI partition".

    I am working on some module, which uses VDS to find volume associated to a particular partition. And we use this information for our internal use.

    I am not able to get any volume Information associated to the EFI partition, and that's the problem for me.

    Initially I thought I am doing something wrong, but found no mount point for EFI partition.

    If EFI partition has no volume associated with it,

    • then how am i able to assign a drive letter to EFI partition and access all files in it as normal windows file system,
    • why is Diskpart showing EFI partition as a volume, (that's confusing me more)

    Please tell me if I am missing out something somewhere.

     
  • Wednesday, February 13, 2013 5:07 PM
     
     
    Sign In to Vote
    0

    Sorry if I was unclear.  What I meant is it is by design that EFI does not show up using mountvol.  You might get better luck using WMI to query and find out the information.

    http://msdn.microsoft.com/en-us/library/windows/desktop/aa393675(v=vs.85).aspx

     
  • Friday, February 15, 2013 11:30 AM
     
     
    Sign In to Vote
    0

    Hi Imperfect1,

    I tried with the WMI calls too, even WMI shows no volume information for the EFI System partition.

    PS C:\Users\Administrator> Get-WmiObject -namespace "root\cimv2" -class Win32_Volume -property DeviceId, Name, Capacity
    Capacity         : 53445914624
    DeviceID         : \\?\Volume{bdb58d69-1f3a-46d6-95e0-2976e82b7b0e}\
    Name             : C:\

    Capacity         :
    DeviceID         : \\?\Volume{04912714-73a1-11e1-8354-806e6f6e6963}\
    Name             : D:\

    PS C:\Users\Administrator> Get-WmiObject -namespace "root\cimv2" -class Win32_MountPoint
    Directory        : Win32_Directory.Name="C:\\"
    Volume           : Win32_Volume.DeviceID="\\\\?\\Volume{bdb58d69-1f3a-46d6-95e0-2976e82b7b0e}\\"

    Directory        : Win32_Directory.Name="A:\\"
    Volume           : Win32_Volume.DeviceID="\\\\?\\Volume{04912715-73a1-11e1-8354-806e6f6e6963}\\"

    Directory        : Win32_Directory.Name="D:\\"
    Volume           : Win32_Volume.DeviceID="\\\\?\\Volume{04912714-73a1-11e1-8354-806e6f6e6963}\\"

    Does anyone out there has a clue on this...