First I close Bitcoin Core...

The size of Bitcoin Core it is 105GB and I want to do pruning so I can have only 2 GB. I make a notepad file named bitcoin.conf and then I write inside prune=2000 or I even tried prune=<2000>.

Then, I have put this file at the install directory or I created the folder Bitcoin and I have put the notepad file in there at the path C:\Users\<user name>\AppData\Roaming\Bitcoin

After all these I open the Bitcoin Core, but nothing happens, it still is 105 GB.

What I am doing wrong? Please help me, I can't understand!

enter image description here

  • 1
    Where did you place bitcoin.conf file? Can you check your debug.log (should be in the same directory)? Also -prune=2000 will not result in a 2GB datadir-size, more 4GB because the UTXO set and header-index will take up some space too. Lowest possible size is -prune=550. Commented Jan 6, 2017 at 11:55
  • I have uploaded a pic that you can see they are in the same folder and I have opened the notepad file I created to see what I have written inside. What am I doing wrong Jonas? Thx in advance!
    – user44839
    Commented Jan 6, 2017 at 12:19
  • related: How can I run bitcoind in pruning mode?
    – Murch
    Commented Jan 6, 2017 at 13:32
  • @JonasSchnelli: Do you know when the pruning would start? Would it be immediately after startup or only e.g. when the next block is added? (See comment on my answer for context.)
    – Murch
    Commented Jan 6, 2017 at 13:36
  • 1
    Pruning is simple, just add -prune=550 to your startup arguments. If you have already synced and verified the chain, it will immediately (at startup) prune the chain. Commented Jan 8, 2017 at 10:29

2 Answers 2


If you put startup commands on the command line, you need to add a dash in the beginning (e.g. bitcoind -prune=2000).

However, when you put them in the bitcoin.conf, I think they have to be put without a dash (e.g. prune=2000). Yet, in the screenshot you show it has a dash. Have you tried putting it in the bitcoin.conf without the dash?

  • Yes, I have tried it and without dash... What should be happening if the prune command works? I mean the 105GB would disappear instantly? I don't know what to do more so I can prune... if anyone can think something is welcomed!
    – user44839
    Commented Jan 6, 2017 at 13:28
  • Not sure, sorry. It should at the latest trigger with the next block discovered though.
    – Murch
    Commented Jan 6, 2017 at 14:03

The problem is right there in your screenshot. You have not actually created the bitcoin.conf. It should not be a text document. On a fresh Windows install the extensions of known file types are hidden by default. Go to Organize -> Folder and search options -> View -> Uncheck Hide extensions for known file types. Then rename bitcoin.conf.txt to bitcoin.conf. Now you have a CONF file.

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