In a method and system for monitoring storage resources, storage containers are monitored to identify their individual normal usage patterns over time. Based on a storage container's normal usage pattern, limits may be established for determining whether its rate of change over a predetermined amount of time (i.e., usage change rate) is normal or abnormal based on a mean and a standard deviation of historical usage rate values. The limits are periodically updated to ensure that the limits remain indicative of the storage container's current usage pattern, as usage patterns may vary over the life of a storage container.