1. Recovery Sites
   1. Redundant sites allow quick recovery in the event of a disaster
   2. Types
      1. Hot Site
         1. Offsite backups that may replace the current active site in case of an adverse security incident
         2. Most expensive
      2. Cold Site
         1. Offsite backups in storage that cannot immediately be brought online in case of a security incident
         2. Least expensive
      3. Warm Site
         1. An offsite location containing the offline hardware that would be required to replace the current active site. Data needed to replace the current active site is not immediately available, but may be accessed.
         2. Middle ground in terms of cost
2. Backup Concepts
   1. Full
      1. All data is backed up. Takes the longest to perform, and the least time to restore, compared to differential or incremental backups.
   2. Differential
      1. At (longer) periodic intervals, a full backup is performed. Between these full backups, the changes that have occurred since then are written.
      2. Unlike incremental backups, multiple instances of differential backups may exist at once, representing different states of a machine.
      3. In order to restore, you need both the most recent full backup and the most recent differential backup.
   3. Incremental
      1. At (longer) periodic intervals, a full backup is performed. Between these full backups, an incremental backup is performed.
      2. Unlike differential backups, incremental backups rewrite (save over) the previous save state. In other words, there is only one incremental backup of a machine at a given time.
      3. In order to restore, you need both the most recent full backup and the incremental backup.
3. Backup Rotation Schemes
   1. Grandfather-Father-Son
      1. The most common backup method used.
      2. When attempting to use this scheme, three sets of backup tapes must be defined—usually they are daily, weekly, and monthly, which correspond to son, father, and grandfather.
      3. Backups are rotated on a daily basis; normally the last one of the week will be graduated to father status.
      4. Weekly (father) backups are rotated on a weekly basis, with the last one of the month being graduated to grandfather status.
      5. Often, monthly (grandfather) backups, or a copy of them, are archived offsite.
   2. 10 Tape Rotation
      1. A simple backup method that provides easy access to data.
      2. It can be accomplished during a two-week backup period; each tape is used once per day for two weeks. Then the entire set is recycled.
   3. Towers of Hanoi
      1. This backup rotation scheme is based on the mathematics of the Towers of Hanoi puzzle. This also uses three backup sets, but they are rotated differently.
      2. The first tape is used every second day, the second tape is used every fourth day, and the third tape is used every eighth day.
      3. A fourth tape can be used every 16th day, and a fifth tape every 32nd day, and so on, although it gets much more complex to remember what tapes to use to back up and which order to go by when restoring.
4. Two Categories of Disasters
   1. Natural
      1. Fire
         1. Fire Suppression
            1. Sprinklers
            2. Gas
            3. Chemical Agents
            4. Wet
            5. Dry
         2. Fire Extinguishers
            1. Types
            2. A
            3. Ash Fires
            4. B
            5. Gas and Flammable Liquid Fires
            6. C
            7. Electrical Fires
         3. Fire Alarms
         4. Fire Drills
      2. Flood
         1. Place Server Rooms on Higher Floors
         2. Do Not Place Server Rooms on the Same Floors as Boiler Rooms
         3. Install Drainage Systems
      3. Power Loss
         1. Short-Term
            1. UPS
         2. Long-Term
            1. Backup Generator
            2. Redundant Site
   2. Man-Made
      1. Theft and Malicious Attacks
         1. Physical Security Controls
            1. Door Locks
            2. CCTV
            3. Cable Locks
            4. Security Guards
5. Disaster Recovery Plans
   1. Contact Information
   2. Impact Determination
   3. Recovery Plan
   4. Copies of Agreements
      1. BPA
      2. SLA
      3. MOU
   5. Business Continuity Plan
      1. Business Impact Analysis
         1. The examination of Critical vs Non-Critical functions
         2. Recovery Time Objective
            1. The acceptable amount of time to restore a function
         3. Recovery Point Objective
            1. The acceptable latency of data, or the maximum tolerable time that data can remain inaccessible after a disaster.
   6. Disaster Recovery Drills and Exercises
   7. Hierarchical Lists of Critical Systems and Critical Data
   8. Geographic Considerations
      1. Off-Site Backups
      2. Distance
      3. Location Selection
      4. Legal Implications
      5. Data Sovereignty
   9. Continuity of Operations Planning
      1. Exercises (Drills)
      2. After-Action Reports
      3. Failover
      4. Alternate Processing Sites
      5. Alternate Business Practices