SMB Works… but My Container Won’t Start

I hit a confusing problem. I could connect to an SMB share.
Windows said everything was fine.

But my Windows container failed to start with errors like:

failed to eval symlinks
The system cannot find the path specified

This post explains why that happens, in simple terms.

What is SMB?

SMB is how computers share folders over a network.

When you see a path like:

\\servername\path

it means:

“This folder lives on another computer, but I can use it.”

SMB is used everywhere for network drives and shared folders.

Why `net use` is misleading

When something fails, people usually try: net use \\ComputerName\SharedFolder

If it works, we assume:

The share exists
Permissions are correct
SMB is working

And we think:

“The problem must be containers.”

That assumption is often wrong.

Humans vs containers

Here’s the key idea:

Containers are stricter than humans.

When you access a folder:

Windows helps you
Shortcuts are followed silently
Weird paths are tolerated

When a container accesses a folder:

No guessing
No shortcuts
Everything must be exact and safe

How containerd resolves paths

Windows containers use a program called containerd.

Before mounting a folder, containerd tries to find the real, final path.

It uses a function called filepath.EvalSymlinks() which:

Follows any shortcuts or redirects
Finds where the folder actually lives
Fails if something blocks the way

If containerd can't resolve the full path, it stops with an error.

Reparse points: folders that lie

A reparse point is a folder that looks real but secretly redirects somewhere else.

Think of it like:

A door that looks normal but opens into a hidden tunnel

Windows is fine with this.
net use is fine with this.

Containers are not.

Why things break

This is why debugging is so painful:

Test	Result
`net use`	✅ Works
Folder exists	✅ Yes
Permissions	✅ Correct
Container start	❌ Fails

Why?

Because:

net use checks access
containerd checks the real path

If the folder is a reparse point that can't be fully resolved, containerd says:

"I can't figure out where this actually goes."

How to check a folder

Windows lets you check whether a folder is hiding something:

fsutil reparsepoint query C:\Your\Folder

If Windows says the folder is not a reparse point: ✅ Containers can use it.

If Windows shows a redirect to another volume: ❌ Containers may fail.

The takeaway

A folder that works for humans may not work for containers.

net use tests access
containerd resolves the full path

Once you understand that difference, these errors finally make sense.