<p>I have bitcoin-qt running on online computer. I want to:</p>

<ol>
<li>copy blockchain to offline computer (preferably using WORM media for security reasons)</li>
<li>from time to time update offline copy with newest blocks with smallest effort. Smallest effort means - among others - that I don't want to re-record whole blockchain from online computer to media every time and would prefer incremental copy instead.</li>
</ol>

<p>The main obstacle that I encountered until now was that - sometimes - when I updated bitcoin-qt on online computer, the 'blocks' directory was wiped out. Then whole blockchain has been re-downloaded, preventing me from copying new blocks incrementally (because for some reason new blk*.dat files had different size/content then previous).</p>

CC BY-SA 4.0
2019-03-12T16:38:05.607Z
There are wallets that explicitly support cold wallets ([example](https://www.bitcoinarmory.com/)) - maybe looking at how those work would help?
RedGrittyBrick
CC BY-SA 4.0
2019-03-12T22:04:55.633Z
@RedGrittyBrick the idea is to allow for verification of transaction history on offline computer, so cold wallet support is not enough.
cryptogopher
CC BY-SA 4.0
2019-03-13T08:55:40.513Z
Ah OK. Interesting project.
RedGrittyBrick
<bitcoin-core><blockchain><client><synchronization><offline>
How to most efficiently keep in sync blockchain on offline computer (including through bitcoin-qt upgrades)?
cryptogopher
# How to most efficiently keep in sync blockchain on offline computer (including through bitcoin-qt upgrades)?

(Asked by: username_0 on 2019-03-12)

I have bitcoin-qt running on online computer. I want to:

1. copy blockchain to offline computer (preferably using WORM media for security reasons)
2. from time to time update offline copy with newest blocks with smallest effort. Smallest effort means - among others - that I don't want to re-record whole blockchain from online computer to media every time and would prefer incremental copy instead.

The main obstacle that I encountered until now was that - sometimes - when I updated bitcoin-qt on online computer, the 'blocks' directory was wiped out. Then whole blockchain has been re-downloaded, preventing me from copying new blocks incrementally (because for some reason new blk\*.dat files had different size/content then previous).

**Tags:** bitcoin-core, blockchain, client, synchronization, offline

> **Comments:**
> **username_1**: There are wallets that explicitly support cold wallets ([example](https://www.bitcoinarmory.com/)) - maybe looking at how those work would help?  
> **username_0**: @username_1 the idea is to allow for verification of transaction history on offline computer, so cold wallet support is not enough.  
> **username_1**: Ah OK. Interesting project.  

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## 0 answers

