How do you configure Windows Subsystem for Linux 2 (WSL2) to use fstab to automatically mount a Windows Network File Share?

Question

I'm trying to mount a windows share (SMB/CIFS) using a Debian 10 linux distribution running on Windows 10's Subsystem for Linux using fstab to automount on startup. My software specs are

OS: Windows 10 Pro 21H2
OS Build: 19044.1526
    
Windows Subsystem for Linux 2 (WSL2)
Distribution: Debian 10.11

According to the following article by Microsoft, you can create a text file at /etc/wsl.conf to store user configuration settings for WSL2.

https://docs.microsoft.com/en-us/windows/wsl/wsl-config

I started using wsl.conf to set the mountFsTab key to true. That should ensure that WSL processes the fstab file. I know the setting should not matter because it defaults to true, but I wanted to make sure it was set to true. My wsl.conf file currently looks like:

# Automatically mount Windows drive when the distribution is launched. 
[automount]
# Automatically mount the fixed drives (C:) under /mnt.
enabled = false
# Sets the `/etc/fstab` file to be processed when a WSL distribution is launched.
mountFsTab = true
        
# Network host settings that enable the DNS server used by WSL 2. This example changes the hostname, sets generateHosts to false, preventing WSL from the default behavior of auto-generating /etc/hosts, and sets generateResolvConf to false, preventing WSL from auto-generating /etc/resolv.conf, so that you can create your own (ie. nameserver 1.1.1.1).
[network] 
hostname = JTI-ITL05-DEBIAN

The hostname does change successfully. However, even when the mountFsTab key is set to true, the fstab file’s mounts are not being applied when the Debian WSL2 instance starts. To test the fstab file, I first tried running the following command.

Sudo mount -a

The command successfully mounts the two entries I have in /etc/fstab. Here is an example of my fstab entries to illustrate the structure using the DrvFs file system plugin Microsoft created for WSL.

#file system                    dir            type    options                         dump    pass
\\\\domain.com\\share\\path     /mnt/mountdir  drvfs   defaults,uid=1000,gid=1000      0       0
C:                              /mnt/c         drvfs   defaults,uid=1000,gid=1000      0       0

To test the processing of fstab, I included a line to mount a local device, drive C in Windows. The line that mounts a local device, mounts successfully when the WSL2 instance starts up. The other line pointing to a Windows network share does not mount on startup, but I can mount it after the instance boots to a terminal CLI. I can confirm the results using the wsl command to shutdown the instance and start it back up. The fstab file is being processed on start up.

I don’t see a relevant log file in /var/log to check for errors. All of my tests have failed so far to get the fstab file to mount a Windows network share when WSL2 Debian starts up.

How do I get the WSL2 instance to automatically mount a Windows network share found in the fstab file?

Answer 1

It turns out I did set everything up correctly. To answer the original question, follow the procedure below to configure Windows Subsystem for Linux 2 (WSL2) to use fstab to automatically mount a Windows Network File Share.

1. Open WSL2 in a terminal.
2. Create a directory to mount the file share. /mnt/mountdir
3. Create a file called "fstab". /etc/fstab
4. Add the following line to the "fstab" file.

\\\\domain.com\\share\\path    /mnt/mountdir    drvfs defaults,uid=1000,gid=1000    0    0

Fill in the share path with a windows share on your network.

I setup a new laptop running Windows 10, followed the procedure above, and confirmed that the Windows share is mounted when the WSL2 instance starts. I'm not sure what the original issue was. It seems to be related to Windows 10 OS corruption. I'll update my answer if I can find the original cause of the issue.

Answer 2

You need to tell fstab to mount automatically at boot.

Change

\\\\domain.com\\shares\\sharename   /mnt/mntdir drvfs       uid=1000,gid=1000   0       0

To

\\\\domain.com\\shares\\sharename   /mnt/mntdir drvfs       defaults,uid=1000,gid=1000   0       0

While auto would be enough, defaults would contain the following options:

 defaults
          Use default options: rw, suid, dev, exec, auto, nouser, and async.