calamares/src/modules/mount/mount.conf

# SPDX-FileCopyrightText: no
# SPDX-License-Identifier: CC0-1.0
#
# Mount filesystems in the target (generally, before treating the
# target as a usable chroot / "live" system). Filesystems are
# automatically mounted from the partitioning module. Filesystems
# listed here are **extra**. The filesystems listed in *extraMounts*
# are mounted in all target systems. The filesystems listed in
# *extraMountsEfi* are mounted in the target system **only** if
# the host machine uses UEFI.
---
# Extra filesystems to mount. The key's value is a list of entries; each
# entry has four keys:
#   - device    The device node to mount
#   - fs (optional) The filesystem type to use
#   - mountPoint Where to mount the filesystem
#   - options (optional) Extra options to pass to mount(8)
#
# The device is not mounted if the mountPoint is unset or if the fs is
# set to unformatted.
#
extraMounts:
    - device: proc
      fs: proc
      mountPoint: /proc
    - device: sys
      fs: sysfs
      mountPoint: /sys
    - device: /dev
      mountPoint: /dev
      options: bind
    - device: tmpfs
      fs: tmpfs
      mountPoint: /run
    - device: /run/udev
      mountPoint: /run/udev
      options: bind

extraMountsEfi:
    - device: efivarfs
      fs: efivarfs
      mountPoint: /sys/firmware/efi/efivars

# Btrfs subvolumes to create if root filesystem is on btrfs volume.
# If *mountpoint* is mounted already to another partition, it is ignored.
# Separate subvolume for swapfile is handled separately and automatically.
#
# It is possible to prevent subvolume creation -- this is likely only relevant
# for the root (/) subvolume -- by giving an empty string as a subvolume
# name. In this case no subvolume will be created. When using snapper as
# a rollback mechanism, it is recommended to **not** create a subvolume
# for root.

btrfsSubvolumes:
    - mountPoint: /
      subvolume: /@
      # As an alternative:
      #
      # subvolume: ""
    - mountPoint: /home
      subvolume: /@home
    - mountPoint: /var/cache
      subvolume: /@cache
    - mountPoint: /var/log
      subvolume: /@log