Cyber Resilience and Redundancy Flashcards
High Availability
● Aims to keep services continuously available by minimizing downtime
● Achieved through load balancing, clustering, redundancy, and multi-cloud
strategies
Uptime
The time a system remains online, typically expressed as a percentage
Five nines
Refers to 99.999% uptime, allowing only about 5 minutes of downtime
per year
Six nines
Refers to 99.9999% uptime, allows just 31 seconds of downtime per year
Load Balancing
Distributes workloads across multiple resources. Incoming requests are directed to capable servers
Clustering
Uses multiple computers, storage devices, and network connections as a single system. Can be combined with load balancing for robust solutions
Redundancy
Involves duplicating critical components to increase system reliability
Multi-Cloud Approach
■ Distributes data, applications, and services across multiple cloud providers
■ Mitigates the risk of a single point of failure
■ Offers flexibility for cost optimization
■ Aids in avoiding vendor lock-in
■ Requires proper data management, unified threat management, and consistent
policy enforcement for security and compliance
Strategic Planning
■ Proactive measures reduce the risk of service disruptions and downtime costs
■ Safeguard organizational continuity and reliability in a competitive environment
RAID
Redundant Array of Independent Disks
Combines multiple physical storage devices into a single logical storage
device recognized by the operating system
RAID 0
■ Provides data striping across multiple disks
■ Used for improved performance but offers no data redundancy
■ Multiple drives increase read and write speeds
■ Suitable for scenarios where performance is essential, and data redundancy is
not a concern
RAID 1
■ Provides redundancy by mirroring data identically on two storage devices
■ Ensures data integrity and availability
■ Suitable for critical applications and maintains a complete copy of data on both
devices
■ Only one storage device can fail without data loss or downtime
RAID 5
■ Utilizes striping with parity across at least three storage devices
■ Offers fault tolerance by distributing data and parity
■ Can continue operations if one storage device fails
■ Data reconstruction is possible but results in slower access speeds
RAID 6
■ Similar to RAID 5 but includes double parity data
■ Requires at least four storage devices
■ Can withstand the failure of two storage devices without data loss
RAID 10
■ Combines RAID 1 (mirroring) and RAID 0 (striping)
■ Offers high performance, fault tolerance, and data redundancy
■ Requires an even number of storage devices, with a minimum of four
RAID Resilience Categories
■ Failure-resistant
● Resists hardware malfunctions through redundancy (e.g., RAID 1)
■ Fault-tolerant
● Allows continued operation and quick data rebuild in case of failure (e.g.,
RAID 1, RAID 5, RAID 6, RAID 10)
■ Disaster-tolerant
● Safeguards against catastrophic events by maintaining data in
independent zones (e.g., RAID 1, RAID 10)
Capacity Planning
Ensures an organization is prepared to meet future demands in a cost-effective
manner
Main aspects of Capacity Planning
- People
- Technology
- Infrastructure
- Processes
Surges
Sudden, small increases in voltage beyond the standard level (e.g., 120V
in the US)
Spikes
Short-lived voltage increases, often caused by short circuits, tripped
breakers, or lightning
Sags
Brief decreases in voltage, usually not severe enough to cause system
shutdown
Undervoltage Events (Brownouts)
Prolonged reduction in voltage, leading to system shutdown
Power Loss Events (Blackouts)
Complete loss of power for a period, potentially causing data loss and
damage
Line Conditioners
● Stabilize voltage supply and filter out fluctuations
● Mitigate surges, sags, and undervoltage events
● Unsuitable for significant undervoltage events or complete power failures
UPS
Uninterruptible Power Supply
● Provide emergency power during power source failures
● Offer line conditioning functions
● Include battery backup to maintain power during short-duration failures
● Typically supply 15 to 60 minutes of power during a complete power
failure
PDC
Power Distribution Centers
● Central hub for power reception and distribution
● Includes circuit protection, monitoring, and load balancing
● Integrates with UPS and backup generators for seamless transitions
during power events
Onsite Backup
Storing data copies in the same location as the original data
Offsite Backup
Storing data copies in a geographically separate location
RPO
Recovery Point Objective
Ensures that the backup plan will maintain the amount of data
required to keep any data loss under the organization’s RPO
threshold
Snapshots
■ Point-in-time copies capturing a consistent state
■ Records only changes since the previous snapshot, reducing storage
requirements
■ Use cases
● Valuable for systems where data consistency is critical, like databases and
file servers
Replication
Real-time or near-real-time data copying to maintain data continuity
Journaling
Maintaining a detailed record of data changes over time
COOP
Continuity of Operations Plan
Ensures an organization’s ability to recover from disruptive events or disasters
BC Plan
Business Continuity Planning
● Plans and processes for responding to disruptive events
● Addresses a wide range of threats and disruptive incidents
● Involves preventative actions and recovery steps
DRP
Disaster Recovery Plan
● Focuses on plans and processes for disaster response
● Subset of the BC Plan
● Focuses on faster recovery after disasters
Business Continuity Committee
Comprises representatives from various departments (IT, Legal, Security,
Communications, etc.)
Determines recovery priorities for different events
Identifies and prioritizes systems critical for business continuity
Redundant Site
Backup location or facility that can take over essential functions and operations
in case the primary site experiences a failure or disruption
Hot Sites
● Up and running continuously, enabling a quick switchover
● Requires duplicating all infrastructure and data
● Expensive, but provides instant availability
Warm Sites
● Not fully equipped, but fundamentals in place
● Can be up and running within a few days
● Cheaper than hot sites but with a slight delay
Cold Sites
● Fewer facilities than warm sites
● May be just an empty building, ready in 1-2 months
● Cost-effective but adds more recovery time
Mobile Sites
● Can be hot, warm, or cold
● Utilizes portable units like trailers or tents
● Offers flexibility and quick deployment (e.g., military DJC2)
Platform Diversity
■ Critical for effective virtual redundant sites
■ Diversify operating systems, network equipment, and cloud platforms
■ Reduces the risk of a single point of failure
■ Ensures resilience and adaptability in case of disruptions
Virtual Sites
Leveraging cloud-based environments for redundancy
Tabletop Exercises
■ Scenario-based discussion among key stakeholders
■ Assess and improve an organization’s preparedness and response
■ No deployment of actual resources
Failover Tests
■ Controlled experiment for transitioning from primary to backup components
■ Ensures uninterrupted functionality during disasters
Simulations
■ Computer-generated representation of a real-world scenario
■ Allows for hands-on response actions in a virtual environment
Parallel Processing
Replicates data and system processes onto a secondary system
