The file systems to be mounted. It must include an entry for the root directory (mountPoint = "/"). Each entry in the list is an attribute set with the following fields: mountPoint, device, fsType (a file system type recognised by mount; defaults to "auto"), and options (the mount options passed to mount using the -o flag; defaults to [ "defaults" ]).

Instead of specifying device, you can also specify a volume label (label) for file systems that support it, such as ext2/ext3 (see mke2fs -L).

attribute set of (submodule)
{ }
  "/".device = "/dev/hda1";
  "/data" = {
    device = "/dev/hda2";
    fsType = "ext3";
    options = [ "data=journal" ];
  "/bigdisk".label = "bigdisk";