diff --git a/nixos/modules/system/boot/systemd.nix b/nixos/modules/system/boot/systemd.nix index f955746f78a0..2167df60bc9a 100644 --- a/nixos/modules/system/boot/systemd.nix +++ b/nixos/modules/system/boot/systemd.nix @@ -593,6 +593,9 @@ in each other's limit. The value may be specified in the following units: s, min, h, ms, us. To turn off any kind of rate limiting, set either value to 0. + + See for important + considerations when setting this value. ''; }; @@ -604,6 +607,19 @@ in interval) that is applied to all messages generated on the system. This rate limiting is applied per-service, so that two services which log do not interfere with each other's limit. + + Note that the effective rate limit is multiplied by a factor derived + from the available free disk space for the journal as described on + + journald.conf(5). + + Note that the total amount of logs stored is limited by journald settings + such as SystemMaxUse, which defaults to a 4 GB cap. + + It is thus recommended to compute what period of time that you will be + able to store logs for when an application logs at full burst rate. + With default settings for log lines that are 100 Bytes long, this can + amount to just a few hours. ''; };