<p>Are you running a sufficiently recent version? If you are running an older version, you would need to have the full blockchain archive to serve compact client-side block filters.<br />
Originally <code>blockfilterindex</code> and pruning were exclusive features. This was only changed recently when PR<a href="https://github.com/bitcoin/bitcoin/pull/15946" rel="nofollow noreferrer">#15946</a> allowed serving compact client-side block filters from pruned nodes. The feature was included in the <strong>Bitcoin Core v22.0</strong> release.</p>
<p>You should be able to trigger the reindex by stopping your Bitcoin Core, and then starting Bitcoin Core with the <code>-reindex</code> startup parameter once.</p>

CC BY-SA 4.0
2022-05-10T00:26:38.650Z
thanks! I'm trying this at the moment, still redownloading the blockchain
Martin Massera
CC BY-SA 4.0
2022-05-09T18:25:40.370Z
2022-05-10T01:26:31.277Z
2022-05-10T01:26:31.277Z
Murch
<p>Bitcoin Core doesn't run in Neutrino mode, it can only <strong>serve</strong> compact filters. Neutrino is a Lightning Lab's implementation of BIP157 and BIP158 basic filter type. It is a standalone backend, and you can run lnd <strong>without</strong> Bitcoin Core.<br />
Moreover, the only way to compute the missing filters is to download all blocks again, compute the filters and then prune again.</p>

CC BY-SA 4.0
2022-05-09T15:24:53.080Z
Thanks, I updated the question
Martin Massera
CC BY-SA 4.0
2022-05-05T21:51:49.560Z
2022-05-05T21:51:49.560Z
Davidson Souza
<p>According to <a href="https://github.com/lightninglabs/docs.lightning.engineering/blob/master/lightning-network-tools/lnd/enable-neutrino-mode-in-bitcoin-core.md" rel="nofollow noreferrer">Lightning Lab's documentation</a>, Bitcoin Core can be run in &quot;neutrino mode&quot; to serve block data without storing transactions.</p>
<p>I've been running Bitcoin Core in pruning mode and everything is okay. Now I would like to enable this mode to serve data for <code>lnd</code>. The documentation says that adding these parameters will set up Bitcoin Core to run in &quot;neutrino mode&quot;:</p>
<pre><code>blockfilterindex=1
peerblockfilters=1
</code></pre>
<p>When I add them, Bitcoin Core gives this error:</p>
<blockquote>
<p>Error: basic block filter index best block of the index goes beyond
pruned data. Please disable the index or reindex (which will download
the whole blockchain again)</p>
</blockquote>
<p>Of course, it is necessary to re-download the blockchain. So my questions are:</p>
<ul>
<li><strong>Will this configuration cause Bitcoin Core to store the entire blockchain, or will it just keep the headers and continue pruning the blocks?</strong></li>
<li><strong>How can a reindex be triggered?</strong></li>
</ul>

<bitcoin-core><lightning-network><pruning><compact-client-side-block-filters>
How do I switch a pruned node to "neutrino mode"?
Martin Massera
# How do I switch a pruned node to "neutrino mode"?

(Asked by: username_0 on 2022-05-05)

According to [Lightning Lab's documentation](https://github.com/lightninglabs/docs.lightning.engineering/blob/master/lightning-network-tools/lnd/enable-neutrino-mode-in-bitcoin-core.md), Bitcoin Core can be run in "neutrino mode" to serve block data without storing transactions.

I've been running Bitcoin Core in pruning mode and everything is okay. Now I would like to enable this mode to serve data for `lnd`. The documentation says that adding these parameters will set up Bitcoin Core to run in "neutrino mode":

```
blockfilterindex=1
peerblockfilters=1

```

When I add them, Bitcoin Core gives this error:

> Error: basic block filter index best block of the index goes beyond
> pruned data. Please disable the index or reindex (which will download
> the whole blockchain again)

Of course, it is necessary to re-download the blockchain. So my questions are:

* **Will this configuration cause Bitcoin Core to store the entire blockchain, or will it just keep the headers and continue pruning the blocks?**
* **How can a reindex be triggered?**

**Tags:** bitcoin-core, lightning-network, pruning, compact-client-side-block-filters


---

## 2 answers

### Answer by username_1 on 2022-05-09. Score: 2 | Accepted answer

Are you running a sufficiently recent version? If you are running an older version, you would need to have the full blockchain archive to serve compact client-side block filters.  
Originally `blockfilterindex` and pruning were exclusive features. This was only changed recently when PR[#15946](https://github.com/bitcoin/bitcoin/pull/15946) allowed serving compact client-side block filters from pruned nodes. The feature was included in the **Bitcoin Core v22.0** release.

You should be able to trigger the reindex by stopping your Bitcoin Core, and then starting Bitcoin Core with the `-reindex` startup parameter once.

> **Comments:**
> **username_0**: thanks! I'm trying this at the moment, still redownloading the blockchain  

---

### Answer by username_2 on 2022-05-05. Score: 3

Bitcoin Core doesn't run in Neutrino mode, it can only **serve** compact filters. Neutrino is a Lightning Lab's implementation of BIP157 and BIP158 basic filter type. It is a standalone backend, and you can run lnd **without** Bitcoin Core.  
Moreover, the only way to compute the missing filters is to download all blocks again, compute the filters and then prune again.

> **Comments:**
> **username_0**: Thanks, I updated the question  

---

