https://www.linuxhosted.com/tags/disk-usage/Recent content in Disk-Usage on LinuxHosted.comHugo -- gohugo.ioenLinuxHosted.comWed, 14 Oct 2026 00:00:00 +0000https://www.linuxhosted.com/post/journald-disk-usage-why-one-log-line-costs-49-kb-how-cap-systemd-journald/Wed, 14 Oct 2026 00:00:00 +0000https://www.linuxhosted.com/post/journald-disk-usage-why-one-log-line-costs-49-kb-how-cap-systemd-journald/ <p>A <a href="https://github.com/systemd/systemd/issues/40262">systemd bug report</a> opened on January 3, 2026, put a number on something Linux admins had long suspected: <strong>systemd-journald</strong> writes far more data to disk than the log text it stores. The reporter, running systemd 257.9 on Debian 13 (kernel 6.12.57+deb13-amd64) with the journal on XFS, saw a virtual machine doing about 50 I/O operations per second while logging two short haproxy lines per second. In August, a systemd contributor measured it directly on ext4: a single short log message produced at least 55KB of disk writes. This guide covers what the report found, why the journal format behaves this way, and which settings in <code>journald.conf</code> actually limit how much disk a server's logs use.</p>