nixos/profiles/zfs.nix

   1 { pkgs, lib, hostName, ... }:
   2 {
   3   # none is the recommended elevator with ZFS (which has its own I/O scheduler)
   4   services.udev.extraRules = ''
   5     ACTION=="add|change", KERNEL=="sd[a-z]*[0-9]*|mmcblk[0-9]*p[0-9]*|nvme[0-9]*n[0-9]*p[0-9]*", ENV{ID_FS_TYPE}=="zfs_member", ATTR{../queue/scheduler}="none"
   6   '';
   7
   8   boot.supportedFilesystems = [ "zfs" ];
   9   boot.initrd.supportedFilesystems = [ "zfs" ];
  10
  11   boot.kernelParams = [
  12     # Disabled because the zfs kernel module is not signed
  13     "module.sig_enforce=0"
  14   ];
  15
  16   # Using ZFS together with hibernation (suspend to disk)
  17   # may cause filesystem corruption.
  18   # See https://github.com/openzfs/zfs/issues/260
  19   boot.zfs.allowHibernation = false;
  20
  21   # Stable enough, clearer, and faster than the default /dev/disk/by-id
  22   boot.zfs.devNodes = "/dev/disk/by-partlabel";
  23   # Not useful so far.
  24   # See also https://github.com/NixOS/nixpkgs/issues/62644#issuecomment-1479523469
  25   boot.zfs.forceImportAll = false;
  26   # More resilient for remote hosts,
  27   # though it may call zpool clear.
  28   boot.zfs.forceImportRoot = true;
  29   boot.zfs.requestEncryptionCredentials = lib.mkDefault [ "${hostName}/root" ];
  30
  31   boot.zfs.enableUnstable = false;
  32
  33   # Enables periodic scrubbing of ZFS pools.
  34   services.zfs.autoScrub.enable = true;
  35   services.zfs.autoScrub.interval = "Sun *-*-08..14 00:15:00";
  36
  37   # According to zpool(8), for consumer hardware
  38   # periodic manual TRIM is preferred over the automatic TRIM
  39   # that ZFS implements.
  40   services.zfs.trim.enable = true;
  41   services.zfs.trim.interval = "Sun *-*-01..07 00:15:00";
  42
  43   # Hide ZFS mountpoints from gio, hence nautilus or caja
  44   systemd.services.zfs-mount.postStart = ''
  45     /run/wrappers/bin/mount -t zfs | cut -f 1 -d ' ' |
  46     xargs -n 1 -r -t /run/wrappers/bin/mount -o remount,x-gvfs-hide
  47   '';
  48
  49   environment.systemPackages = [
  50     pkgs.lzop # For remote syncoid
  51     pkgs.mbuffer # For remote syncoid
  52     pkgs.sanoid
  53   ];
  54
  55   # Force zpool import, even if the disk has not been exported,
  56   # (ie. still imported onto another computer).
  57   systemd.services."zfs-import@" = {
  58     description = "ZFS import pool: %I";
  59     unitConfig = {
  60       ConditionPathIsDirectory = "/sys/module/zfs";
  61       StartLimitIntervalSec = 0;
  62     };
  63     after = [ "systemd-modules-load.service" ];
  64     path = lib.mkBefore [ "/run/booted-system/sw" ];
  65     serviceConfig = {
  66       Type = "oneshot";
  67       RemainAfterExit = true;
  68       PrivateTmp = true;
  69       SyslogIdentifier = "zfs-import@%i";
  70       Restart = "no";
  71       ExecStart = pkgs.writeShellScript "zfs-import" ''
  72         pool="$1"
  73         set -eux
  74         zpool import -lFd /dev/disk/by-id/ -o cachefile=none "$pool" ||
  75         zpool reopen "$pool" ||
  76         zpool import -lfd /dev/disk/by-id/ -o cachefile=none "$pool" ||
  77         zpool clear -nFX "$pool"
  78         ${pkgs.systemd}/bin/systemctl restart zfs-mount.service
  79       '' + " %I";
  80     };
  81   };
  82 }