<p>If you want custom file handling, you'll need to alter the client code, or write some application that would be reading from the dat file and splitting it accordingly. I haven't heard of any existing offline solutions for alternative handling of the files.</p>

CC BY-SA 3.0
2011-11-21T10:59:37.687Z
2011-11-21T10:59:37.687Z
ThePiachu
<p>This is actually already implemented: blk0001.dat contains the first two gigabytes of blockchain data, blk0002.dat contains the second two gigabytes, and so on. We just haven't hit two gigabytes of data yet.</p>

CC BY-SA 3.0
2011-11-22T17:49:55.907Z
one gigabyte is much stuff...
glglgl
CC BY-SA 3.0
2011-11-22T21:34:06.757Z
@glglgl You can request a feature for the Main Client to offer variable size of .dat dumps here: https://github.com/bitcoin/bitcoin , although I don't think it will be a high priority, unless it turns out that a lot of other people want the same.
ThePiachu
CC BY-SA 3.0
2011-11-22T17:31:22.530Z
2012-05-31T08:59:55.680Z
2012-05-31T08:59:55.680Z
Pieter Wuille
<p>From <a href="https://github.com/bitcoin/bitcoin/issues/1400#issuecomment-6028443" rel="nofollow">https://github.com/bitcoin/bitcoin/issues/1400#issuecomment-6028443</a>, Gregory Maxwell explains that blk0001.dat will contain closer to 2GB of blockchain data.  He also explained that a gambling site and a miner with an inefficient payout system are responsible for the fast increase in file size.</p>

CC BY-SA 3.0
2012-05-31T06:06:18.300Z
2012-05-31T06:06:18.300Z
Dave Scotese
<p>As the mere size of the constantly changing data file tampers with my backup concept, I would like to ask if there is a way to split this file into many smaller pieces. I have no problem with the size as such, but with the amount of changes.</p>

<p>Background is, I do my backups with <code>rsnapshot</code>. This links files which haven't been changed on the target together, while changed files are copied in full.</p>

<p>That's why I would imagine to split the currently about 763 MB big <code>blk0001.dat</code> into two files:</p>

<ul>
<li><code>blk0001.dat</code> having maybe 700 MB, and not changing (frequently) in the future.</li>
<li><code>blk0002.dat</code> holding the rest.</li>
</ul>

<p>As the 2nd file grows steadily, I would, after it has reached a certain size, put more data from it into <code>blk0001.dat</code>, and eventually stop changing this file at all, starting a 3rd one.</p>

<p>Has someone done this already?</p>

CC BY-SA 3.0
2011-11-21T14:07:08.667Z
Just in case you're unaware, backing up your bitcoins only requires wallet.dat, not the block chain data.
Meni Rosenfeld
CC BY-SA 3.0
2011-11-21T14:38:50.863Z
Yes, but I don't want to download all that stuff in a case of emergency... that needed me 2 days or so the last time...
glglgl
CC BY-SA 3.0
2011-11-21T14:39:14.357Z
OTOH: as I have it on 3 computers, I exclude it everywhere from the backup. Good point!
glglgl
CC BY-SA 3.0
2011-11-21T22:50:52.683Z
@glglgl You can always use e-wallets if you really want the emergency access time - https://en.bitcoin.it/wiki/Category:EWallets
ThePiachu
CC BY-SA 3.0
2011-11-22T08:58:10.230Z
Backing up my wallet is no problem. I am just worried about the huge files. But if I just exclude them from backup, all is fine.
glglgl
CC BY-SA 3.0
2011-11-24T08:04:04.020Z
And, as I just noticed: if I lose them all, I can [re-download them as an archive](http://bitcoin.stackexchange.com/questions/799/can-i-download-the-whole-block-chain-from-somewhere).
glglgl
<blockchain><bitcoind><raw-data>
Limit size of data files
glglgl
# Limit size of data files

(Asked by: username_0 on 2011-11-21)

As the mere size of the constantly changing data file tampers with my backup concept, I would like to ask if there is a way to split this file into many smaller pieces. I have no problem with the size as such, but with the amount of changes.

Background is, I do my backups with `rsnapshot`. This links files which haven't been changed on the target together, while changed files are copied in full.

That's why I would imagine to split the currently about 763 MB big `blk0001.dat` into two files:

* `blk0001.dat` having maybe 700 MB, and not changing (frequently) in the future.
* `blk0002.dat` holding the rest.

As the 2nd file grows steadily, I would, after it has reached a certain size, put more data from it into `blk0001.dat`, and eventually stop changing this file at all, starting a 3rd one.

Has someone done this already?

**Tags:** blockchain, bitcoind, raw-data

> **Comments:**
> **username_1**: Just in case you're unaware, backing up your bitcoins only requires wallet.dat, not the block chain data.  
> **username_0**: Yes, but I don't want to download all that stuff in a case of emergency... that needed me 2 days or so the last time...  
> **username_0**: OTOH: as I have it on 3 computers, I exclude it everywhere from the backup. Good point!  
> **username_2**: @username_0 You can always use e-wallets if you really want the emergency access time - https://en.bitcoin.it/wiki/Category:EWallets  
> **username_0**: Backing up my wallet is no problem. I am just worried about the huge files. But if I just exclude them from backup, all is fine.  
> **username_0**: And, as I just noticed: if I lose them all, I can [re-download them as an archive](http://bitcoin.stackexchange.com/questions/799/can-i-download-the-whole-block-chain-from-somewhere).  

---

## 3 answers

### Answer by username_2 on 2011-11-21. Score: 2 | Accepted answer

If you want custom file handling, you'll need to alter the client code, or write some application that would be reading from the dat file and splitting it accordingly. I haven't heard of any existing offline solutions for alternative handling of the files.


---

### Answer by username_3 on 2011-11-22. Score: 5

This is actually already implemented: blk0001.dat contains the first two gigabytes of blockchain data, blk0002.dat contains the second two gigabytes, and so on. We just haven't hit two gigabytes of data yet.

> **Comments:**
> **username_0**: one gigabyte is much stuff...  
> **username_2**: @username_0 You can request a feature for the Main Client to offer variable size of .dat dumps here: https://github.com/bitcoin/bitcoin , although I don't think it will be a high priority, unless it turns out that a lot of other people want the same.  

---

### Answer by username_4 on 2012-05-31. Score: 2

From <https://github.com/bitcoin/bitcoin/issues/1400#issuecomment-6028443>, Gregory Maxwell explains that blk0001.dat will contain closer to 2GB of blockchain data. He also explained that a gambling site and a miner with an inefficient payout system are responsible for the fast increase in file size.


---

