Successful recovery from data loss generally requires implementation of an effective backup strategy. Without an implemented backup strategy, recovery requires reinstallation of programs and regeneration of data. Even with an effective backup strategy, restoring a system to the precise state it was in prior to the "Data Loss Event" is extremely difficult. Some level of compromise between granularity of recoverability and cost is necessary. Furthermore, a "Data Loss Event" may not be immediately apparent. An effective backup strategy must also consider the cost of maintaining the ability to recover lost data for long periods of time.