I just downloaded Bitcoin-QT, and torrented a snapshot of the block chain that is a couple weeks old. I put the bootstrap.dat in ~/Library/Application Support/Bitcoin and started up the app. Right now it is "Importing blocks from disk". Where do the blocks goes once they've been imported? A friend of mine says that the Bitcoin app makes a Merkle tree out of the blocks in the block chain. How is this stored? I want to write a program that takes snapshots of the block chain every couple hours. It would be much better if I could just update a copy of the block chain as needed instead of making an entire new copy and deleting the old copy.

How do I make a bootstrap.dat out of the blkXXXXX.dat files?

2 Answers 2


You will find the .dat files in the following locations:

  • Linux: ~/.bitcoin/blocks
  • MacOS: ~/Library/Application Support/Bitcoin/blocks
  • Windows: %APPDATA%Bitcoin\blocks
  • WinXP: C:\Documents and Settings\YourUserName\Application data\Bitcoin\blocks
  • Win7/Win8/Vista: C:\Users\YourUserName\AppData\Roaming\Bitcoin\blocks

I always found the following attached image helpful in order to understand the structure of the dat files. I am sure it will help you too.

.dat files data structure


In windows it is stored in Local>AppData>Bitcoin folder on linux it is stored in the Bitcoin folder > blockchain and then blkxxx.dat


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