1
0
Fork 1
mirror of https://github.com/NixOS/nixpkgs.git synced 2024-12-13 16:15:30 +00:00
nixpkgs/modules/config/swap.nix
2012-10-12 17:32:36 -04:00

114 lines
3.1 KiB
Nix
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

{ config, pkgs, utils, ... }:
with pkgs.lib;
with utils;
{
###### interface
options = {
swapDevices = mkOption {
default = [];
example = [
{ device = "/dev/hda7"; }
{ device = "/var/swapfile"; }
{ label = "bigswap"; }
];
description = ''
The swap devices and swap files. These must have been
initialised using <command>mkswap</command>. Each element
should be an attribute set specifying either the path of the
swap device or file (<literal>device</literal>) or the label
of the swap device (<literal>label</literal>, see
<command>mkswap -L</command>). Using a label is
recommended.
'';
type = types.list types.optionSet;
options = {config, options, ...}: {
options = {
device = mkOption {
example = "/dev/sda3";
type = types.uniq types.string;
description = "Path of the device.";
};
label = mkOption {
example = "swap";
type = types.uniq types.string;
description = ''
Label of the device. Can be used instead of <varname>device</varname>.
'';
};
size = mkOption {
default = null;
example = 2048;
type = types.nullOr types.int;
description = ''
If this option is set, device is interpreted as the
path of a swapfile that will be created automatically
with the indicated size (in megabytes) if it doesn't
exist.
'';
};
};
config = {
device =
if options.label.isDefined then
"/dev/disk/by-label/${config.label}"
else
mkNotdef;
};
};
};
};
config = mkIf ((length config.swapDevices) != 0) {
system.requiredKernelConfig = with config.lib.kernelConfig; [
(isYes "SWAP")
];
# Create missing swapfiles.
# FIXME: support changing the size of existing swapfiles.
boot.systemd.services =
let
createSwapDevice = sw:
assert sw.device != "";
let device' = escapeSystemdPath sw.device; in
nameValuePair "mkswap-${escapeSystemdPath sw.device}"
{ description = "Initialisation of Swapfile ${sw.device}";
wantedBy = [ "${device'}.swap" ];
before = [ "${device'}.swap" ];
path = [ pkgs.utillinux ];
script =
''
if [ ! -e "${sw.device}" ]; then
fallocate -l ${toString sw.size}M "${sw.device}" ||
dd if=/dev/zero of="${sw.device}" bs=1M count=${toString sw.size}
mkswap ${sw.device}
fi
'';
unitConfig.RequiresMountsFor = [ "${dirOf sw.device}" ];
unitConfig.DefaultDependencies = false; # needed to prevent a cycle
serviceConfig.Type = "oneshot";
};
in listToAttrs (map createSwapDevice (filter (sw: sw.size != null) config.swapDevices));
};
}