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.

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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.

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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.

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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

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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.

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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.

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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."

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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.

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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.