systemd-makefs@.service, systemd-mkswap@.service, systemd-growfs@.service, systemd-growfs-root.service, systemd-makefs, systemd-growfs — Creating and growing file systems on demand
systemd-makefs@device.service
systemd-mkswap@device.service
systemd-growfs@mountpoint.service
systemd-growfs-root.service
/usr/lib/systemd/systemd-makefs
/usr/lib/systemd/systemd-growfs
systemd-makefs@.service,
    systemd-mkswap@.service,
    systemd-growfs@.service, and
    systemd-growfs-root.service are used to implement the
    x-systemd.makefs and x-systemd.growfs options
    in fstab(5),
    see systemd.mount(5).
    They are instantiated for each device for which the file system or swap structure
    needs to be initialized, and for each mount point where the file system needs to
    be grown.
These services are started at boot, either right before or right after the mount point or swap device are used.
systemd-makefs knows very little about specific file
    systems and swap devices, and after checking that the block device does not already
    contain a file system or other content, it will execute binaries specific to
    each filesystem type (/sbin/mkfs.
    or type/sbin/mkswap). For certain file system types (currently
    ext2/ext3/ext4(5),
    btrfs(5),
    xfs(5),
    f2fs, vfat) and for swap devices, it will configure reasonable defaults and set
    the file system label and UUID based on the device name.
systemd-growfs knows very little about specific file
    systems and swap devices, and will instruct the kernel to grow the mounted
    filesystem to full size of the underlying block device. Nevertheless, it needs
    to know the
    ioctl(2)
    number specific to each file system, so only certain types are supported.
    Currently:
    ext4(5),
    btrfs(5),
    xfs(5),
    
    and dm-crypt partitions (see
    cryptsetup(8)).
    
If the creation of a file system or swap device fails, the mount point or swap is failed too. If the growing of a file system fails, a warning is emitted.