Raspberry Pi OS • zram+file not respecting FixedSizeMiB

Why is the zram+file config not honoring the FixedSizeMiB size? It seems to be fixing it to the size of RAM.

free -h
total used free shared buff/cache available
Mem: 906Mi 242Mi 327Mi 5.7Mi 404Mi 663Mi
Swap: 905Mi 0B 905Mi

less /etc/rpi/swap.conf
# This file is part of rpi-swap.
#
# Defaults are provided as commented-out options. Local configuration
# should be created by either modifying this file, or by creating "drop-ins" in
# the swap.conf.d/ subdirectory. The latter is generally recommended.
#
# See swap.conf(5) for details.

[Main]
Mechanism=zram+file

[File]
#Path=/var/swap
#RamMultiplier=1
#MaxSizeMiB=2048
#MaxDiskPercent=50
FixedSizeMiB=2044

[Zram]
#RamMultiplier=1
#MaxSizeMiB=2048
#FixedSizeMiB=
# Writeback settings (for zram+file mechanism):
#WritebackTrigger=auto
#WritebackInitialDelay=180min
#WritebackPeriodicInterval=24h

journalctl -b -u dev-zram0.swap
Nov 11 13:52:11 raspberrypi3b systemd[1]: Activating swap dev-zram0.swap - rpi-swap managed swap device (zram+file)...
Nov 11 13:52:11 raspberrypi3b systemd[1]: Activated swap dev-zram0.swap - rpi-swap managed swap device (zram+file).

systemctl list-units --quiet --type=swap
dev-zram0.swap loaded active active rpi-swap managed swap device (zram+file)

uname -a
Linux raspberrypi3b 6.12.47+rpt-rpi-v8 #1 SMP PREEMPT Debian 1:6.12.47-1+rpt1 (2025-09-16) aarch64 GNU/Linux

lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description: Debian GNU/Linux 13 (trixie)
Release: 13
Codename: trixie

Statistics: Posted by inthexor — Tue Nov 11, 2025 8:22 pm

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