The debug.log file is getting pretty big on bitcoind. How do you limit the size of the file? I'm on Ubuntu 12.


You can use logrotate.
Create a file named bitcoin-debug in /etc/logrotate.d.

This is the contents:

        rotate 5

Replace /home/bitcoin/.bitcoin/debug.log with the actual path to your debug.log file.

The full logrotate manpage is here: http://manpages.ubuntu.com/manpages/jaunty/man8/logrotate.8.html

UPDATE: In ubuntu the logrotate daemon manages many different log files. In the /etc/logrotate.d folder, each file contains instructions for the logrotate deamon. Adding this file tells logrotate that you want to copy and then truncate the debug.log once a day. The other options tell it to compress the old logs after a day and to keep only 5 older logs.

I originally found out about logrotate from this thread: https://bitcointalk.org/index.php?topic=130533.0

  • i dont get how this works. can you explain. thanks! – Patoshi パトシ Dec 17 '13 at 17:46
  • do i need to do anything to kick off the daemon, or does it automatically start doing it? – tofutim Apr 5 '18 at 20:25
  • logrotate runs by default in ubuntu so you don't need to do anything other than adding files to the /etc/logrotate.d folder. – hsmiths May 12 '18 at 18:52

Add -shrinkdebuglog to the options you use to start bitcoin, or add shrinkdebuglog=1 to your bitcoin.conf.

Every startup, if the log is larger than 1MB, it will shrink it to 200KB.


Alternatively, you can use printtoconsole to redirect the debug output to the console instead of the debug.log file.

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