nixdots/system/shared/services/fstrim.nix
2024-07-27 01:07:07 +02:00

40 lines
1.1 KiB
Nix

{
config,
lib,
...
}: let
inherit (lib.modules) mkIf;
in {
# if lvm is enabled, then tell it to issue discards
# (this is good for SSDs and has almost no downsides on HDDs, so
# it's a good idea to enable it unconditionally)
environment.etc."lvm/lvm.conf".text = mkIf config.services.lvm.enable ''
devices {
issue_discards = 1
}
'';
# discard blocks that are not in use by the filesystem, good for SSDs
services.fstrim = {
# we may enable this unconditionally across all systems becuase it's performance
# impact is negligible on systems without a SSD - which means it's a no-op with
# almost no downsides aside from the service firing once per week
enable = true;
# the default value, good enough for average-load systems
interval = "weekly";
};
# tweak fstim service to run only when on AC power
# and to be nice to other processes
# (this is a good idea for any service that runs periodically)
systemd.services.fstrim = {
unitConfig.ConditionACPower = true;
serviceConfig = {
Nice = 19;
IOSchedulingClass = "idle";
};
};
}