Commit e07671cc authored by Mynacol's avatar Mynacol
Browse files

nixos/btrfs: Add option to limit scrub throughput

parent b1de421a

nixos/modules/tasks/filesystems/btrfs.nix

+13 −1
Original line number Diff line number Diff line
@@ -65,6 +65,16 @@ in 
        '';

      };



      limit = mkOption {

        default = null;

        type = types.nullOr (types.strMatching "[0-9]+[KMGT]?");

        example = "100M";

        description = ''

          The scrub throughput limit applied on all scrubbed filesystems.

          The value is bytes per second, and accepts the usual KMGT prefixes.

        '';

      };



    };

  };
@@ -185,7 +195,9 @@ in 
                Type = "simple";

                Nice = 19;

                IOSchedulingClass = "idle";

                ExecStart = "${pkgs.btrfs-progs}/bin/btrfs scrub start -B ${fs}";

                ExecStart = "${pkgs.btrfs-progs}/bin/btrfs scrub start -B ${

                  lib.optionalString (cfgScrub.limit != null) "--limit ${cfgScrub.limit}"

                } ${fs}";

                # if the service is stopped before scrub end, cancel it

                ExecStop = pkgs.writeShellScript "btrfs-scrub-maybe-cancel" ''

                  (${pkgs.btrfs-progs}/bin/btrfs scrub status ${fs} | ${pkgs.gnugrep}/bin/grep finished) || ${pkgs.btrfs-progs}/bin/btrfs scrub cancel ${fs}