Part 12 - update Raspberry Pi OS Trixie (2025) and increase swap to 4 GB

Raspberry Pi OS Trixie (2025) 

Expand Swap Using dphys-swapfile (Bookworm and Older).

Expand Swap Using rpi-swap (Trixie and Newer).

 

Raspberry Pi OS Trixie (2025) or newer, the system uses rpi-swap instead of dphys-swapfile. 

 

rpi-swap is a new package that replaces/deprecates dphys-swapfile for configuring swap on your Raspberry Pi.it is a standard swap management solution, providing better performance and reliability than the old dphys-swapfile approach.

Supports: Compressed RAM swap (zram), file-based swap, or hybrid modes.

Using zram avoids small/frequent writes to /var/swap so as to increase SD card longevity. 

 

Raspberry OS Version

cat /etc/os-release
PRETTY_NAME="Debian GNU/Linux 13 (trixie)"
NAME="Debian GNU/Linux"
VERSION_ID="13"
VERSION="13 (trixie)"
VERSION_CODENAME=trixie
DEBIAN_VERSION_FULL=13.4
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"

System Requirements

Raspberry Pi OS Trixie (2025) or newer

rpi-swap is installed.

Raspberry Pi OS Trixie (2025)  uses rpi-swap:

Config Directory: /etc/rpi/swap.conf (drop-in configuration files).

Default Swap Type: Compressed RAM swap (zram).

Default Swap File: /dev/zram0.

Default Size: Up to 2048MB, sized to match RAM (capped at 50% of disk space).

Supports: Compressed RAM swap (zram), file-based swap, or hybrid modes.

 

rpi-swap

rpi-swap GitHub Repository (Official):https://github.com/raspberrypi/rpi-swap

Modern swap management for Raspberry Pi systems, designed to replace dphys-swapfile with a more flexible and efficient approach.

 

Check Current Swap Configuration

 

Check total swap size and usage:

free -h

 free -h
               total        used        free      shared  buff/cache   available
Mem:           7.9Gi       5.7Gi       342Mi       2.7Mi       2.0Gi       2.2Gi
Swap:          2.0Gi       2.0Gi       656Ki

 

Check swap details

cat /proc/meminfo | grep Swap

 

 cat /proc/meminfo | grep Swap
SwapCached:           48 kB
SwapTotal:       2097136 kB
SwapFree:          26944 kB

 

see where the swap file is located:

 

swapon --show

 swapon --show
NAME       TYPE      SIZE USED PRIO
/dev/zram0 partition   2G   0B  100

 

rpi-swap uses systemd generators so 'rpi-zram-writeback' will not appear in the list of package files.

tree /run/systemd/generator/

 tree /run/systemd/generator/
/run/systemd/generator/
├── boot-firmware.mount
├── dev-zram0.swap
├── getty.target.wants
│   └── [email protected] -> /usr/lib/systemd/system/[email protected]
├── local-fs.target.requires
│   ├── boot-firmware.mount -> ../boot-firmware.mount
│   └── -.mount -> ../-.mount
├── local-fs.target.wants
│   ├── systemd-fsck-root.service -> /usr/lib/systemd/system/systemd-fsck-root.service
│   └── systemd-remount-fs.service -> /usr/lib/systemd/system/systemd-remount-fs.service
├── -.mount
├── netplan.stamp
├── rpc_pipefs.target
├── [email protected]
│   ├── fast-symlink.conf
│   ├── no-dependency-cycle.conf
│   └── resize-swap.conf
├── rpi-zram-writeback.timer
├── run-rpc_pipefs.mount
├── sockets.target.wants
│   └── sshd-unix-local.socket -> ../sshd-unix-local.socket
├── [email protected] -> /usr/lib/systemd/system/[email protected]
├── sshd-unix-local.socket
├── swap.target.wants
│   └── dev-zram0.swap -> ../dev-zram0.swap

 

 

 install/configure rpi-swap (Trixie only):

sudo apt install rpi-swap
sudo reboot

 

Configuration files are located at:

/etc/rpi/swap.conf

 

detailed configuration options

man swap.conf

 

verify that swap has been configured properly:

systemctl list-units --type swap

systemctl list-units --type swap
  UNIT           LOAD   ACTIVE SUB    DESCRIPTION                             
  dev-zram0.swap loaded active active rpi-swap managed swap device (zram+file)

Legend: LOAD   → Reflects whether the unit definition was properly loaded.
        ACTIVE → The high-level unit activation state, i.e. generalization of SUB.
        SUB    → The low-level unit activation state, values depend on unit type.

1 loaded units listed. Pass --all to see loaded but inactive units, too.
To show all installed unit files use 'systemctl list-unit-files'.

 

References

rpi-swap GitHub Repository (Official):https://github.com/raspberrypi/rpi-swap