Commit 8e0e9bde authored by Jonathan Davies's avatar Jonathan Davies
Browse files

nixos/zfs: Added a randomizedDelaySec option to ZFS autoscrub/trim timers 

Allows operators to space out these IO operations across a fleet of
machines, rather than have them all happen at the same time.
parent b3741ce0

nixos/modules/tasks/filesystems/zfs.nix

+29 −1
Original line number Diff line number Diff line
@@ -441,6 +441,18 @@ in 
          {manpage}`systemd.time(7)`.

        '';

      };



      randomizedDelaySec = mkOption {

        default = "6h";

        type = types.str;

        example = "12h";

        description = ''

          Add a randomized delay before each ZFS trim.

          The delay will be chosen between zero and this value.

          This value must be a time span in the format specified by

          {manpage}`systemd.time(7)`

        '';

      };

    };



    services.zfs.autoScrub = {
@@ -456,6 +468,18 @@ in 
        '';

      };



      randomizedDelaySec = mkOption {

        default = "6h";

        type = types.str;

        example = "12h";

        description = ''

          Add a randomized delay before each ZFS autoscrub.

          The delay will be chosen between zero and this value.

          This value must be a time span in the format specified by

          {manpage}`systemd.time(7)`

        '';

      };



      pools = mkOption {

        default = [];

        type = types.listOf types.str;
@@ -862,6 +886,7 @@ in 
        timerConfig = {

          OnCalendar = cfgScrub.interval;

          Persistent = "yes";

          RandomizedDelaySec = cfgScrub.randomizedDelaySec;

        };

      };

    })
@@ -879,7 +904,10 @@ in 
        serviceConfig.ExecStart = "${pkgs.runtimeShell} -c 'for pool in $(zpool list -H -o name); do zpool trim $pool;  done || true' ";

      };



      systemd.timers.zpool-trim.timerConfig.Persistent = "yes";

      systemd.timers.zpool-trim.timerConfig = {

        Persistent = "yes";

        RandomizedDelaySec = cfgTrim.randomizedDelaySec;

      };

    })

  ];

}