Disaster Recovery and The Seven Tiers of BCP
The seven tiers of disaster recovery were developed in the late 1980s by the SHARE Technical Steering Committee and IBM are a still used currently by enterprises as a measurement of priority. Each Business Continuity Plan (BCP) is defined by the Recovery Point Objective (RPO) and the Recovery Time Objective (RTO) and thus, categorized in tier levels. It is important to differentiate between the tiers, which are defined as the following:
Tier 0: Potential no recovery, no off-site data
This 0-level tier indicates an organization with no BCP, no saved information, no documentation and no backup. Potentially no recovery.
Tier 1: Backup data with no “hot site”
Tier 1 refers to an organization that sends backup data to an off-site storage facility; for example, backing up on tape and trucking it to a remote location. If a disaster hits, the organization must be prepared to suffer several days to weeks of data loss though their backup is on an off-site. This tier lacks systems to fully restore data.
Tier 2: Backup data with a “hot site”
Tier 2 describes an organization that backups data frequently. Combined with an off-site facility and “hot site” to restore systems from backup tapes during a disaster. Recovery time in Tier 2 is more predictable but will still result in the need to recreate hours of days’ worth of data.
Tier 3: Electronic vaulting
Tier 3 has the major components of Tier 2 such as off-site backups, a Disaster Recovery Plan and a “hot site”. However, Tier 3 augments backup through electronically vaulted data. Recovery time is estimated to be usually 24 hours.
Tier 4: Point-in-time copies
This tier solution indicates organizations that need great data currency and faster recovery than the users of the lower tiers. Tier 4 solutions incorporate ore disk-based solutions. Data loss of several hours is still possible, but it is easer to make point-in-time copies with increased frequency.
Tier 5: Transaction integrity
Organizations that use Tier 5 solutions require data consistency between the production data center and recovery data centers. There is little or no data loss in these solutions.
Tier 6: Zero or near-zero data loss
Tier 6 solutions exemplify the highest levels of data currency – with little or no tolerance for data loss. Restoration of data needs is a high priority. Tier 6 solution often requires some form of disk mirroring or automated tape solutions.
Tier 7: Highly automated, business integrated solution
The top tier, Tier 7, incorporates all the components used for Tier 6 solutions with integrated automation. Recovery of applications is automated and brings a faster level of restoration of systems.
Overall, as explained above, a wide range of solutions is available for organizations to implement with their Disaster Recovery Plan. However, there is no singular solution that will be a perfect fit for every enterprise; in fact, a combination of different tiers can potentially provide more benefits. Therefore, various methods of backup, multiple locations, and a fusion of tiers can build upon each other as means of augmenting Disaster Recovery.