1.8 KiB
File Systems
You can define file systems using the fileSystems 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";
};
This will create an entry in /etc/fstab, which will generate a
corresponding systemd.mount
unit via systemd-fstab-generator.
The filesystem will be mounted automatically unless "noauto" is
present in options. "noauto"
filesystems can be mounted explicitly using systemctl e.g.
systemctl start data.mount. Mount points are created automatically if they don't
already exist. For device, 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 (fsType), 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 fsType to ensure that the kernel module is available.
::: {.note}
System startup will fail if any of the filesystems fails to mount,
dropping you to the emergency shell. You can make a mount asynchronous
and non-critical by adding options = [ "nofail" ];.
:::
<xi:include href="luks-file-systems.section.xml" />
<xi:include href="sshfs-file-systems.section.xml" />