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    [archiso] Add optional OverlayFS support · a637bdb8
    Gerardo Pozzi authored
    This is the first attemp to test overlayfs in archiso.
    The current dm-snapshot mode is keep and is enabled by default,
    while the new mode is enabled via "-s sfs" to mkarchiso.
    No new boot parameters are added, since archiso hooks detects
    if the .sfs file is for dm-snapshot (airootfs.img inside)
    or for overlayfs.
    Persistence is supported in overlayfs mode using the same options
    (cowlabel or cowdevice), but warning while in dm-snapshot mode,
    only one file is used (airootfs.cow), in overlayfs mode internal
    files for workdir/ and upperdir/ are allocated, so you can not use
    VFAT or NTFS.
    To test this, you need to enable [testing] in pacman.conf from
    releng profile and edit then add "-s sfs" in make_prepare()
    Look at:
        setarch ${arch} mkarchiso ${verbose} -w "${work_dir}" -D "${install_dir}" prepare
    Replace with:
        setarch ${arch} mkarchiso ${verbose} -w "${work_dir}" -s sfs -D "${install_dir}" prepare
    The build requires just half of space that the build for dm-snapshot,
    since there is no ext4 img ;)
    Just to remember: there is no space gain in .sfs (just about 2M)
    There is at least one thing during boot with machine-id service:
    Dec 24 03:31:39 archiso systemd-machine-id-commit[183]: Failed to unmount transient /etc/machine-id file in our private namespace: Invalid argument
    Signed-off-by: default avatarGerardo Exequiel Pozzi <>