Unable to access UNC path via windows service even when using same user for service

Question

I have a windows vm and have created an Admin user, let's say - AdminUser. I have mounted an azure file share to that user to Z: drive. The share can be accessed by unc path or the drive path. I also have a c# utility that checks if path exists and it returns true when I run it. This is all good. Now when I created a windows service with that utility and with same user credential, it throws an error that the path doesn't exist. Things to note -

• The service user or the user I used to login is a local adminstrator user and while creating the service, I had provided as "./AdminUser" to CreateService. Also provided password to config.
• The VM is also connected to a domain. So I have users from default-domain\* and connected-domain\*. The connected-domain linked to an azure active directory.

Is there any other type of user I need to set as log on to service?

I can see here it says the local user can't access network resources but I am wondering since I mounted the path with proper credentials, does this matter?

Update: Got the same issue when using running as with the exe.

runas /user:USER­NAME “C:\full\path\of\Program.exe”

Answer 1

We have to use cmdkey to store the credentials that can be used by SMB later. Launch a cmd.exe with the user that you want to use for the service using either context menu or command e.g.

runas /user:default-domain\domainServiceUser cmd

Then in the new command shell use cmdkey

cmdkey /add:<storagteAccountName>.file.core.windows.net\<shareName> /user:AZURE\<storageAccountName> /pass:<storageAccountKey>

Rerun the service and it should work.

If you want to also mount this as a persistent drive, you can use

Command Prompt

net use z: \\<storagteAccountName>.file.core.windows.net\<shareName> /persistent:yes

Powershell

New-PSDrive -Name Z -PSProvider FileSystem -Root "\\<storagteAccountName>.file.core.windows.net\<shareName>" -Persist

Make sure that the user is exactly the same that would be used for the windows service including the domain i.e. use default-domain\domainServiceUser or ./AdminUser for running the cmdkey.

Answer 2

Though the user account is same, when the windows service runs as a 'user' the logon session that it gets is different than the interactive user session (which has the Z drive). Unless you programmatically load the Azure fileshare as a network drive in your code that is part of the Windows service, you won't be able to access it.