types: Update description for setting 'Guaranteed Engine CPU'
Longhorn
@@ -344,7 +344,13 @@ var (
SettingDefinitionGuaranteedEngineCPU = SettingDefinition{
DisplayName: "Guaranteed Engine CPU",
- Description: "Allow Longhorn Instance Managers to have guaranteed CPU allocation. The value is how many CPUs should be reserved for each Engine/Replica Instance Manager Pod created by Longhorn. For example, 0.1 means one-tenth of a CPU. This will help maintain engine stability during high node workload. It only applies to the Engine/Replica Manager Pods created after the setting took effect. WARNING: After this setting is changed, all the instance managers on all the nodes will be automatically restarted. \nWARNING: DO NOT CHANGE THIS SETTING WITH ATTACHED VOLUMES.",
+ Description: "Allow Longhorn Instance Managers to have guaranteed CPU allocation. The value is how many CPUs should be reserved for each Engine/Replica Instance Manager Pod created by Longhorn. For example, 0.1 means one-tenth of a CPU. This will help maintain engine stability during high node workload. It only applies to the Engine/Replica Instance Manager Pods created after the setting took effect. \n" +
+ "In order to prevent unexpected volume crash, you can use the following formula to calculate an appropriate value for this setting: \n" +
+ "Guaranteed Engine CPU = The estimated max Longhorn volume/replica count on a node * 0.1 \n" +
+ "The result of above calculation doesn't mean that's the maximum CPU resources the Longhorn workloads require. To fully exploit the Longhorn volume I/O performance, you can allocate/guarantee more CPU resources via this setting. \n" +
+ "If it's hard to estimate the volume/replica count now, you can leave it with the default value, or allocate 1/8 of total CPU of a node. Then you can tune it when there is no running workload using Longhorn volumes. \n" +
+ "WARNING: After this setting is changed, all the instance managers on all the nodes will be automatically restarted. \n" +
+ "WARNING: DO NOT CHANGE THIS SETTING WITH ATTACHED VOLUMES.",
Category: SettingCategoryDangerZone,
Type: SettingTypeString,
Required: true,
