Mount drives and access content from inside module function

PowerShell Help
1

Example to recreate the issue.

When mounting an VHDX either with Mount-WindowsImage or Mount-VHD from inside a function that is part of a module. I cant access the content of that VHDX.
But if the function is dot sourced it works fine.

This is on V4 and V5.
Does anyone know of a workaround?

2

Does it throw an error? If so could you post the error. Almost sounds like a scope issue, but I can’t see anything that points to that off the bat.

3

PS H:\downloads\temp2> .\Fails.ps1

DriveLetter FileSystemLabel FileSystem DriveType HealthStatus OperationalStatus SizeRemaining Size

        Windows Recovery NTFS       Fixed     Healthy      OK                   1000.34 MB 1023.87 MB

DiskPath: \?\scsi#disk&ven_msft&prod_virtual_disk#2&1f4adffe&0&000004#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}

PartitionNumber DriveLetter Offset Size Type

1 F 65536 1023.88 MB Recovery

Out-File : Cannot find drive. A drive with the name ‘F’ does not exist.
At H:\downloads\temp2\Test.psm1:22 char:18

  • 'test 123' | Out-File $file

  •              ~~~~~~~~~~~~~~
    • CategoryInfo : ObjectNotFound: (F:String) [Out-File], DriveNotFoundException
    • FullyQualifiedErrorId : DriveNotFound,Microsoft.PowerShell.Commands.OutFileCommand

Get-ChildItem : Cannot find drive. A drive with the name ‘F’ does not exist.
At H:\downloads\temp2\Test.psm1:23 char:5

  • Get-ChildItem $file

  • ~~~~~~~~~~~~~~~~~~~
    • CategoryInfo : ObjectNotFound: (F:String) [Get-ChildItem], DriveNotFoundException
    • FullyQualifiedErrorId : DriveNotFound,Microsoft.PowerShell.Commands.GetChildItemCommand

PS H:\downloads\temp2> .\Always-Work.ps1

DriveLetter FileSystemLabel FileSystem DriveType HealthStatus OperationalStatus SizeRemaining Size

        Windows Recovery NTFS       Fixed     Healthy      OK                   1000.34 MB 1023.87 MB

DiskPath: \?\scsi#disk&ven_msft&prod_virtual_disk#2&1f4adffe&0&000005#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}

PartitionNumber DriveLetter Offset Size Type

1 F 65536 1023.88 MB Recovery

Directory: F:\

Mode LastWriteTime Length Name

-a---- 8/20/2015 11:58 AM 22 temp.txt

PS H:\downloads\temp2> .\Fails.ps1

DriveLetter FileSystemLabel FileSystem DriveType HealthStatus OperationalStatus SizeRemaining Size

        Windows Recovery NTFS       Fixed     Healthy      OK                   1000.34 MB 1023.87 MB

DiskPath: \?\scsi#disk&ven_msft&prod_virtual_disk#2&1f4adffe&0&000006#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}

PartitionNumber DriveLetter Offset Size Type

1 F 65536 1023.88 MB Recovery

Directory: F:\

Mode LastWriteTime Length Name

-a---- 8/20/2015 11:59 AM 22 temp.txt

4

I found a connect from 2013 regarding this issue.

https://connect.microsoft.com/PowerShell/Feedback/Details/804580

5

Yup, I was about to go there to see if I could find the problem as a bug. Seems like there is a possible workaround posted on connect you could use, if you didn’t already see that.

Workaround that was posted for the connect Bug that was filed.

$mount = Mount-DiskImage $isoPath -PassThru
$driveLetter = ($mount | Get-Volume).DriveLetter

# Have to use New-PSDrive so other cmdlets in this session can see the new drive
New-PSDrive -Name $driveLetter -PSProvider FileSystem -Root "$($driveLetter):\"

// ...do things...

Dismount-DiskImage $mount.ImagePath
6

I’m going to try that once I get home.

That fix begs the question. If a dot sourced function mounts a drive. then dismounts it. Does the PSDrive not get removed and the Module function just reuses it.

More testing is in order.

7

That workaround mentioned did work. but poking around if found that after assigning a letter to the volume all I need to do was run
$null = get-psdrive
and the drive would be available. Not really a true fix but it’s working.