Switch from Bitcoin Core to Knots (Windows, Mac, Linux, Start9, Umbrel, MyNode, Raspiblitz)

Bitcoin
1

I published my next Bitcoin video tutorial. In this one, I demonstrate how to make your voice heard in the ongoing Spam War, by switching from Bitcoin Core to Knots and making sure your node is publicly reachable and being counted among the nodes who are running Bitcoin Knots.

2

Great idea for a video, Paul, looks pretty comprehensive too. I think this will help a lot of newbies like myself. So many videos on YT skip the foundation work and jump straight to the later subject. A lot of people new to bitcoin or to dev sw / processes get lost trying to follow along.

3

Paul , do you troubleshoot Umbrel nodes , have this error below

2025-07-14T12:42:04Z : Error initializing block database.
Please restart with -reindex or -reindex-chainstate to recover.
2025-07-14T12:42:04Z [error] Aborted block database rebuild. Exiting.
2025-07-14T12:42:04Z Shutdown: In progress…
: Error initializing block database.
Please restart with -reindex or -reindex-chainstate to recover.
2025-07-14T12:42:04Z scheduler thread exit
2025-07-14T12:42:04Z Flushed fee estimates to fee_estimates.dat.
2025-07-14T12:42:05Z Shutdown: done

4

I have less experience with Umbrel than Start9, but I do recognize that error. It is usually caused by either a power outage or improperly powering off the server while it is in the middle of writing a block to the database. It will require re-indexing the blockchain. I found this post which mentions how to do it.

5

I looked at the post , my issue is with the terminology and different senarios used, these are the things that not very elementary too me with no formal training , only step by step YouTube instruction really help, I know how to get to the terminal on my Mac, not sure how in this situation .
My Umbrel OS is running on a Dell laptop with linux os, no other programs running ,
What would be the steps to get to SSH into the laptop to encounter the commands in the post.

6

I haven’t tested this, but according to my LLM, the process should be (let me know if you get to a step that fails):

1. Stop Bitcoin Knots first

  1. On the Mac, open http://umbrel.local (or the IP address of the Umbrel box) and log in.
  2. Find Bitcoin Knots in the App list, click the ⋯ (three‑dots) menu ➜ Stop.
  • Wait until the status badge turns red (“Stopped”). This keeps the file we’ll edit from being in use.

2. Open Umbrel’s built‑in Terminal

  1. Still in the Umbrel web UI, go to Settings → Advanced → Terminal → Open.
  • Umbrel will pop up a browser‑based terminal window (no extra software needed)

3. Tell Knots to re‑index

Copy the entire gray line below and paste it into the terminal, then press Return:

sudo nano ~/umbrel/app-data/bitcoin-knots/data/bitcoin/bitcoin.conf
  • nano opens the config file in a simple text editor.
  • Use the ↓ arrow to reach the end of the file, then add this new line on its own:
reindex=1
  • Save and exit Nano: Ctrl‑X, then Y, then Return.

You can now close the terminal tab.

4. Start the re‑index

Back in the Umbrel dashboard: three‑dots ➜ Start on Bitcoin Knots.
What happens now?

  • Knots will rebuild its block and index files. The UI will say “Syncing / Verifying blocks”.
  • Depending on the hardware, this will usually take around a day. Leave the node powered on and connected.

5. When it finishes, remove the re‑index flag

  1. Once Knots shows “Synced” and stays there for at least 10–15 minutes, press ⋯ → Stop again.

  2. Re‑open the terminal and run the same nano command as before.

  3. Delete the reindex=1 line you added earlier.

  4. Save and exit Nano: Ctrl‑X, then Y, then Return.

  5. Back in the dashboard, Start Bitcoin Knots one last time. It should now launch normally without starting another re‑index.

7

The first time I put in commands all went well, knots began syncing fine, as my luck goes had a bad thuderstorm overnight and power went out.Finally Got everything back on line , re ran the commands now getting this error. not sure what it means?

Error: Error reading configuration file: Failed to include configuration file umbrel-bitcoin.conf1

8

Since it needs to reindex anyway, it might be simpler to just uninstall then reinstall Knots, to start over with a clean slate.

9

Ok on my umbrel node I have knots and core installed, will I need to use uninstall both and start over or just knots , not sure how they interact with each other, my understanding is the knots depends on core to work properly

10

Do you use Core for anything? I think you whould be able to uninstall both and just reinstall Knots, unless there is a service which requires it and doesn’t have an option to use Knots instead. On Umbrel, they have their own separate copies of the blockchain database, though, so if one is corrupt it doesn’t necessarily mean the other is also.