Configure Bitcoin
liongrass / May 2023 (402 Words, 3 Minutes)
Configuring Bitcoin Core
Before we start Bitcoin Core for the first time, we are going to configure it with the minimal settings. We are going to add other configuration options later as we need them.
First, we are going to create a configuration file and place it in the directory where Bitcoin Core can find it as we start it up.
Useful resources:
Create a configuration file
If you installed Bitcoin Core from source or downloaded the binaries, make a folder called .bitcoin in your home directory, then open a text editor to place the config file here.
mkdir ~/.bitcoin
nano ~/.bitcoin/bitcoin.conf
If you installed Ubuntu from the Ubuntu Snap Store, you can directly edit the configuration file with:
nano ~/snap/bitcoin-core/common/.bitcoin/bitcoin.conf
We can use the following sample configuration file, adjust it to our needs and paste it into the editor. Lines that begin with a pound sign (#) represent comments and will not be read by Bitcoin Core. They exist to maximize our understanding of what each line does and how we can configure it. Feel free to remove these comments, or add your own.
# The directory we want to use to store the blockchain. If you are using a single drive, remove this setting. Otherwise, specify the path of your external drive.
datadir=/mnt/bitcoin
# We prune the blockchain to 40GB so that it fits on our 50GB drive.
# The other 10GB will be free to be taken by other data of Bitcoin Core, such as the UTXO set.
prune=40000
We can now save this file (Ctrl + O) + (Enter) to confirm filename and exit (Ctrl + X) the editor.
Start Bitcoin Core
To start Bitcoin Core, we use the command:
bitcoind --daemon
We should see the message: Bitcoin Core starting.
If you installed Bitcoin Core from the Ubuntu Snap Store, the correct command to start the program is:
bitcoin-core.daemon --daemon
Observe the logs
We can now follow the log files with this command. Adjust the path if your bitcoin directory is elsewhere:
tail -f /mnt/bitcoin/debug.log
We can exit this log by pressing Ctrl + C.
You may exit the terminal now at any time by typing exit. Bitcoin Core should keep running as long as the computer is not turned off. You should be able to check on your progress anytime by logging into your machine and following the logs as above.
Your logs will likely show mostly lines like the ones below as it is syncing. The progress variable shows your approximate progress in percent, while the date shows the day on which the block was mined that your node just synchronized. The height variable shows the block height. You will notice that syncing through the first five to seven years of Bitcoin is relatively quick, while the past five years will take relatively long.
2025-08-20T02:36:42Z UpdateTip: new best=00000000000000008776caa976d96ed7906146f2c0c62b06b1f42015db6033c7 height=277020 version=0x00000002 log2_work=75.151666 tx=29924089 date='2013-12-26T08:53:01Z' progress=0.024338 cache=670.1MiB(5447553txo)
2025-08-20T02:36:42Z UpdateTip: new best=0000000000000002354b56bf3c2c3055d967d75bc4771944b23f5c4748e3ac9e height=277021 version=0x00000002 log2_work=75.151840 tx=29924312 date='2013-12-26T09:00:23Z' progress=0.024338 cache=670.1MiB(5447215txo)
2025-08-20T02:36:42Z UpdateTip: new best=0000000000000002e3a28c8b0b7d3f6de2737cc07f8adf74e887926a901a0d94 height=277022 version=0x00000002 log2_work=75.152015 tx=29924546 date='2013-12-26T09:07:01Z' progress=0.024338 cache=670.1MiB(5447221txo)