Knowledge Base
Systemd-tmpfiles
2 min read

systemd-tmpfiles is a utility within systemd that automates the creation, cleanup, and deletion of volatile and temporary files and directories based on configuration files. It helps manage commonly used paths such as /tmp, /run, /var/tmp, /sys, and /proc, ensuring proper setup during boot and clean-up during uptime.

Configuration Files: tmpfiles.d

Configuration files live in directories such as:

• /etc/tmpfiles.d/*.conf
• /run/tmpfiles.d/*.conf
• /usr/local/lib/tmpfiles.d/*.conf
• /usr/lib/tmpfiles.d/*.conf
• ~/.config/user-tmpfiles.d/*.conf
• $XDG_RUNTIME_DIR/user-tmpfiles.d/*.conf
• ~/.local/share/user-tmpfiles.d/*.conf

Format

Each config line consists of:

Type Path Mode User Group Age Argument

Syntax Overview

Types

Here are some key line types:

TypeDescription
f, f+Create (or truncate with +) a file; write content if provided (f+ always).
w, w+Write to an existing file; + appends. Supports globs.
d, Dd: create directory; D: same, but contents removed with --remove.
eAdjust existing directory (mode/owner), optionally clean contents based on age.
p, p+Create FIFO; p+ replaces any existing file.
L, L+Create symlink (with forced replacement if +).

Age Field

Used for cleanup decisions, it expresses time offsets using suffixes like s, m/min, h, d, w, etc. Defaults to seconds if no suffix is given. Combine multiple units like 1d2h.

An Age prefixed with ~ applies cleanup only one level deep. Omitting or using - disables automatic cleanup.

Using age = 0 means unconditional cleanup upon every run.

Mode, User, Group

• Mode, User, Group: adjust permissions and ownership.
• Numeric IDs or names accepted. - means use the invoking user (for user-mode runs).
• Prefixing user/group with : only affects inode creation, not modifications to existing entries.(Freedesktop[2])

Usage

bash
# Create defined files & dirs
sudo systemd-tmpfiles --create

# Clean based on age
sudo systemd-tmpfiles --clean

# Remove items flagged for deletion
sudo systemd-tmpfiles --remove

# Combine remove and create (common during boot)
sudo systemd-tmpfiles --remove --create

# User mode (no sudo)
systemd-tmpfiles --user --create

Examples

Creating and Cleaning a Directory

Add to /etc/tmpfiles.d/my.conf:

conf
d /tmp/myapp 0755 myuser mygroup 1h -