<p>According to <a href="https://askubuntu.com/questions/411375/deduplication-using-sdfs-file-system">this</a>, you need 4096 bytes to align to actually deduplicate (or rather, save space). If I'm reading correctly, that means you would need the same 4096 bytes to occur in the blockchain somewhere at which point you would save space.</p>

<p>Given that each block has all sorts of essentially random data (tx id's block id's, signatures, etc), I would think 4096 bytes aligning anywhere would be highly unlikely. Most likely, you wouldn't actually save any disk space.</p>

CC BY-SA 3.0
2015-03-15T17:44:56.163Z
TXID, block ID, and signatures are randomly generated, but they're the same between clients.
Nick ODell
CC BY-SA 3.0
2015-03-15T17:48:44.880Z
I think I'm not understanding something. Are you sharing the same drive across the multiple computers? And are you running different clients or the same client on the multiple computers?
Jimmy Song
CC BY-SA 3.0
2015-03-15T17:55:58.443Z
`Are you sharing the same drive across the multiple computers?` Yes, but they have different data directories. `And are you running different clients or the same client on the multiple computers?` Different clients, but all of them are the same version.
Nick ODell
CC BY-SA 3.0
2015-03-15T17:58:31.817Z
In that case, I misunderstood. If you have essentially the same data, yes, you should see significant data deduplication. Depending on how the data is arranged, if you have 10 copies of the .bitcoin directory, for example, most of 9 other copies should be saved. Hard to know exactly how much until you actually try it, though. Sorry I can't be more helpful.
Jimmy Song
CC BY-SA 3.0
2015-03-15T14:55:56.763Z
2015-03-15T14:55:56.763Z
2017-04-13T12:23:01.473Z
Jimmy Song
<p>Suppose you have multiple computers on the same network. Also, you use a block-level (note that 'block' is different in this context than what it usually means in Bitcoin) deduplication filesystem  like <a href="http://opendedup.org/quickstart" rel="nofollow">SDFS</a> to deduplicate blocks between these computers.</p>

<p>How much disk space would this save when running Bitcoin Core? Assume that all of the computers are running the same version of <code>bitcoind</code>.</p>

<storage-footprint>
How much space does deduplication save?
Nick ODell
# How much space does deduplication save?

(Asked by: username_0 on 2015-03-14)

Suppose you have multiple computers on the same network. Also, you use a block-level (note that 'block' is different in this context than what it usually means in Bitcoin) deduplication filesystem like [SDFS](http://opendedup.org/quickstart) to deduplicate blocks between these computers.

How much disk space would this save when running Bitcoin Core? Assume that all of the computers are running the same version of `bitcoind`.

**Tags:** storage-footprint


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## 1 answers

### Answer by username_1 on 2015-03-15. Score: 1

According to [this](https://askubuntu.com/questions/411375/deduplication-using-sdfs-file-system), you need 4096 bytes to align to actually deduplicate (or rather, save space). If I'm reading correctly, that means you would need the same 4096 bytes to occur in the blockchain somewhere at which point you would save space.

Given that each block has all sorts of essentially random data (tx id's block id's, signatures, etc), I would think 4096 bytes aligning anywhere would be highly unlikely. Most likely, you wouldn't actually save any disk space.

> **Comments:**
> **username_0**: TXID, block ID, and signatures are randomly generated, but they're the same between clients.  
> **username_1**: I think I'm not understanding something. Are you sharing the same drive across the multiple computers? And are you running different clients or the same client on the multiple computers?  
> **username_0**: `Are you sharing the same drive across the multiple computers?` Yes, but they have different data directories. `And are you running different clients or the same client on the multiple computers?` Different clients, but all of them are the same version.  
> **username_1**: In that case, I misunderstood. If you have essentially the same data, yes, you should see significant data deduplication. Depending on how the data is arranged, if you have 10 copies of the .bitcoin directory, for example, most of 9 other copies should be saved. Hard to know exactly how much until you actually try it, though. Sorry I can't be more helpful.  

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