File SystemsYou can define file systems using the
configuration option. For instance, the
following definition causes NixOS to mount the Ext4 file system on
device /dev/disk/by-label/data onto the mount
point /data:
fileSystems."/data" =
{ device = "/dev/disk/by-label/data";
fsType = "ext4";
};
Mount points are created automatically if they don’t already exist.
For , it’s best to use the topology-independent
device aliases in /dev/disk/by-label and
/dev/disk/by-uuid, as these don’t change if the
topology changes (e.g. if a disk is moved to another IDE
controller).You can usually omit the file system type
(), since mount can usually
detect the type and load the necessary kernel module automatically.
However, if the file system is needed at early boot (in the initial
ramdisk) and is not ext2, ext3
or ext4, then it’s best to specify
to ensure that the kernel module is
available.