Hey everyone,

 

I’m new here! About two weeks ago, I started building my first home server and spent a lot of time researching different OS options. That’s when I came across Unraid, and after diving deeper, I found it to be an amazing choice for my setup.

 

During my research, I discovered that Unraid is based on Slackware Linux. However, I also learned that Unraid is often referred to as a closed-source OS. After looking into it further, I found that not all parts of Unraid are closed source—some components, like its modified md driver (which handles the parity-based array system), are open-source and licensed under GPLv2.

 

However, what confuses me is this:

 

The WebUI PHP files are viewable and editable. While this doesn’t necessarily mean they are "open source," we do have access to them.

 

So which parts of Unraid are actually closed-source?

 

Is it just the emhttp backend binary that is proprietary, or are there other critical components that are not open? if yes what are they?

 

 

I’d love to get some insights from experienced Unraid users and developers. Thanks in advance!

I can't answer all of that, but the webui and many other primary components can be found here: https://github.com/unraid

4 hours ago, b00tkitism said:

I’d love to get some insights from experienced Unraid users and developers. Thanks in advance!

I'm not sure if it is still the case, but almost everything of unraid is open and/or free, including the driver which is in /usr/src after booting, the only part that isn't is how the array is created.

6 hours ago, Wody said:

I'm not sure if it is still the case, but almost everything of unraid is open and/or free, including the driver which is in /usr/src after booting, the only part that isn't is how the array is created.

It's probably in a bash script or something. I'm looking for it.

4 minutes ago, b00tkitism said:

It's probably in a bash script or something. I'm looking for it.

The emhttp binary that is responsible behind the scenes for managing many aspects of Unraid is definitely closed source.   Not sure if other critical items such as 'mover' will be similar.

Based on my research, Unraid's storage-related functionalities are largely open-source, but the way Unraid interfaces with its storage system is proprietary.

What’s Open Source?

• The Unraid kernel module (md/unraid) registers two proc entries under /proc:
  • mdcmd – Handles array creation, parity control, and other storage operations.
  • mdstats – Provides status information about the array.
  • The modified md driver (which implements Unraid’s parity-based storage) is released under GPLv2, meaning all storage-related operations at the kernel level are open-source.
• What’s Closed Source?
  • The user-space communication with mdcmd is not open-source.
  • Multiple components interact with mdcmd, including:
    • The WebUI
    • The emhttpd daemon (Unraid's proprietary management service)
    • Mover
    • Unraid Wake On Lan Daemon
    • shfs (?) It does the same thing that MergerFS does.
    • cgroup2-unraid (?)
    • Other system scripts and services

This means that while the storage driver itself is open, the logic that controls how Unraid manages and interacts with storage devices is proprietary.

Final Answer:

1. All core storage-related operations (parity handling, array management, etc.) are open-source.
2. The closed-source part of Unraid is how it orchestrates storage devices and communicates with the kernel driver via mdcmd.

Would love to hear thoughts from others—did I miss anything?

Edited January 31, 20251 yr by b00tkitism
adding more details

Not sure if the GUI counts as open source or not?   Its code is freely available, but Limetech control whether PRs giving changes get accepted into a release or not.