How to Modify Warewulf Logging

Arsalan Zaidi
Customer Support Engineering Team Lead

May 19, 2025

Introduction

warewulfd can generate massive log output when runtime overlays are transferred—especially across large clusters. This guide applies to Warewulf 4.6.x and shows how to limit that noise by adjusting the log level, helping you preserve disk space and focus on the logs that matter. This is the officially documented and recommended approach per the Warewulf project.

Problem

By default, warewulfd logs each request and overlay file transfer at INFO and SERV levels. In clusters with many nodes, this results in gigabytes of log data being generated, making it hard to isolate real issues and consuming disk space rapidly.

Symptoms

The system logs show repetitive entries such as:

wwctl[3151507]: request from hwaddr:xx:xx:xx:xx:xx:xx ipaddr:10.x.x.x | stage:runtime
wwctl[3151507]: SERV   : stage_file '/var/lib/warewulf/provision/overlays/node/__RUNTIME__.img'
wwctl[3151507]: send /var/lib/warewulf/provision/overlays/node/__RUNTIME__.img.gz -> node

These log messages appear once per provisioning request, per node.

Resolution

To reduce the logging output, increase the warewulfd log level to WARN (this equates to a number of 30 in the configuration). This filters out routine INFO and SERV messages while still logging warnings and errors.

Set the new log level and restart the service:

echo WAREWULFD_LOGLEVEL=30 >> /etc/default/warewulfd
systemctl restart warewulfd.service

This will apply the new log level setting via the EnvironmentFile used by the systemd service.

Root Cause

The default verbosity includes operational messages that are safe to suppress in most environments. At scale, these messages generate high log volumes unnecessarily.

Notes

The following values are confirmed log level values for warewulf:

INFO = 20
SERV = 25
WARN = 30

Restarting the service is required for the changes to take effect.

In Warewulf 4.6.0, PR #1229 restructured the logging by removing the custom SEND and RECV log levels and moving transfer messages to the standard INFO level. The WAREWULFD_LOGLEVEL environment variable via /etc/default/warewulfd remains the supported mechanism for controlling log verbosity.

References & related articles

Warewulf Troubleshooting GitHub Issue #725 - warewulf server should be able to omit send/recv log messages GitHub PR #1229 - Simplify wwctl server command and logging