Each disk quota can have one or more alarm limits (thresholds). An alarm limit is a percentage based on the quota size.
Example: As a network administrator you configure SpaceGuard SRM to place disk quotas on all your users home directories. The fixed quota size is 50MB and your defined alarm limits are 80%, 90%, and 100%. If a user goes over 80% of their disk quota alarm limit a popup is sent. When they go over 90% an email and popup are sent. When they reach 100% of their disk quota limit you revoke their write access.
Fixed quota size, 50MB: