In this lesson,
we will learn about recovery strategies.
Recovery strategies involve planning
and implementing methods to restore systems
and services to operational status
after disruptions or failures.
Recoverability methods include backups
and failover mechanisms to ensure
that systems can be quickly restored after disruption.
Let's learn more about recoverability backups
and failover mechanisms.
In an enterprise environment, one
of our top priorities is ensuring the recoverability
of critical systems and data in the event of a disaster.
Recoverability refers to the organization's ability
to restore normal operations as quickly
and effectively as possible after an incident.
To achieve this, we develop disaster recovery plans
that clearly outline the step by step-by-step procedures
for recovering systems, applications, and data.
For example, if a company's domain controller goes down
due to a cyber attack,
the disaster recovery plan outlines the exact steps
to switch to backups and restore operations.
These plans should include roles
and responsibilities as well as recovery time objectives
or RTOs and recovery point objectives
or RPOs, which set out how quickly we need
to restore critical systems
and how much data loss is acceptable during a disaster.
A key aspect of recovery planning
involves having a backup strategy.
For instance, in the case of a ransomware attack,
having backups ensures you don't lose critical data.
There are several different types of backups.
Full backups create a complete copy of all data,
but take longer and use more storage.
A full backup is like copying an entire hard drive.
Incremental backups save changes since the last incremental
or full backup.
Incremental backups are quicker and more efficient,
but involve restoring from multiple incremental backup files
if a full recovery is needed, and that's complex.
Meanwhile, differential backups capture all changes since
the last full backup, making it easier to restore data
because at most, only the last full backup
and the most recent differential backup are required
for a full recovery.
Last, synthetic full backups administratively combined, full
and incremental or differential backups
to create a new complete backup without having
to copy everything again from the system.
Saving time and resources.
Beyond backups.
Failover mechanisms enable the continuance of operations
during system failures.
A practical example is a website staying online
even if one server crashes.
Thanks to failover mechanisms, there are two main types
of failover mechanisms.
Active-active failover, and active-standby failover.
In an active-active system, both the primary
and backup systems are running at the same time,
so if one fails, the other takes over immediately.
Conversely, in an active standby setup,
one system is active while the other is in standby mode,
ready to take over if the first one fails.
Finally, to ensure all these strategies work effectively,
regular disaster recovery tests are essential.
Disaster recovery test types include tabletop testing,
parallel testing, simulation testing,
and full interruption testing.
In tabletop testing, key team members
review the disaster recovery plan step-by-step.
In parallel testing, backup systems are activated
alongside the main systems
to ensure they work without causing production downtime.
Simulation testing goes a step further
by creating a mock disaster to test
how well your team responds, still
without shutting anything down on the production network.
More advanced testing includes full interruption testing.
In a full interruption test, systems are taken offline
and backups take over, demonstrating failover
and recovery from a real but inserted disaster.
So remember in an enterprise environment,
ensuring the recoverability of critical systems
and data is a top priority.
This involves creating disaster recovery plans
that outline the steps for restoring systems
and data after an incident.
Disaster recovery plans require clear roles,
responsibilities, and recovery objectives.
Indirect support of recovery.
A strong backup strategy is essential.
Different types of backups, like full, incremental,
differential, and synthetic, help ensure
that data can be restored quickly and efficiently.
Additionally, fail over mechanisms such as active-active,
and active-standby systems allow operations
to continue smoothly if a system fails,
and finally, to make sure these strategies work.
Regular disaster recovery tests,
including tabletop, parallel, simulation,
and full interruption testing are crucial
for validating the plan's effectiveness.