Service not recognizing network drive

Was running duplicati as a user, but to properly use VSS I installed duplicati as a service. Then imported my backup config from JSON - no errors. Backup source is a network drive that’s only available when I’m connected to my company VPN.

When running as user, that wasn’t an issue. Now I connect to my VPN and can access the network drive all right, but the duplicati service can’t “see” it and always tell me “source path […] does not exist.”. But it’s right there in the explorer and I can browse it without issues.

If I configure the backup, the network drive and its corresponding drive letter is not shown.
Ideas?

Hello

You will not be able to use VSS with a network drive. VSS means to freeze the computer to block concurrent accesses for a limited time, and that’s allow the computer to take a snapshot. You can’t freeze another computer, so your computer can’t snapshot another computer.

I know that. “Want to use VSS” was just the reason for installing duplicati as a service, I should have left that information out. It has nothing to do with the question at hand.

Duplicati can’t backup from a network drive, even if said network drive is connected in windows and can be used normally. Ideas?

there are tons of ways of having a service using a networked drive, unfortunately most of them have been disabled by Microsoft on the basis that it was pointless and unsecure to begin with, and it’s definitely not a supported configuration.

You can try to:

  • leave the service at the default configuration and use the psexec utility to open a shell as system and map a drive. I have not used this approach since a long time and I’m not optimistic for psexec to still work for ever with modern Windows versions.

  • setup the service to login as your user account, and then map a drive with new-smbglobalmapping (and possibly restart the Duplicati service as well) when your vpn is connected.

Oh, I see. You mean the service, running under a system account, simply has no permissions on that network drive? Then I’ll find my way around that, TY.

the problem is actually that the service does not run through a standard user logon process.

You can run Duplicati as a service using your regular user credentials. This allows it to do things not available to LocalSystem like reading EFS files that your user account encrypted, or accessing network resources, etc.

What I do on my own system instead of using a service is the Task Scheduler approach. Take Duplicati out of the Startup folder and create a task that is triggered when my user logs in. Task Scheduler has an option to run a program elevated. This way I can use VSS and Duplicati still runs as a regular user process (not a service).

Services and Redirected Drives gives an idea of how compartmentalized things can be on Windows.