Chapter 9 Flashcards
Resilience and Physical Security (34 cards)
Continuity of Operations
Ensuring that operations will continue even if issues ranging from single system failures to wide-scale natural disasters occur.
Geographic Dispersion
Placing systems or datacenters at least 90 miles apart. This ensures that a single disaster, attack, or failure cannot disable or destroy them.
Load Balancing
Makes Multiple systems or services appear to be a single resource allowing both redundancy and increased ability to handle loads by distributing them to more than one system.
Clustering
Used to allow groups of computers to perform the same task, but without a load balancer cannot provide the same transparent service appearing as the same system
Uninterruptible Power Supply (UPS)
A device that can provide short-term power, usually by using batteries.
Dual-Supply System
Also known as multisupply hardware, ensures that a power supply failure won’t disable a server.
Managed Power Distribution Units (PDUs)
Used to provide intelligent power management and remote control of power delivered inside server racks and other environments.
High Availability
It keeps systems running despite failures, ensuring continuous access without manual intervention
Redundant Arrays of Inexpensive Disks (RAID)
RAID uses multiple disks with striped (spread) or mirrored (duplicated) data, plus parity to prevent corruption or loss. It allows disk failure without losing data.
Journaling
A data protection option. It logs changes for recovery, allowing databases to restore to a specific point in time.
Recovery Point Objectives (RPO)
A measure of how much loss can be accepted by the organization when a disaster occurs. RPO is the maximum amount of time that can elapse between your backups, thus determining how much data could be lost in a disaster.
Recovery Time Objectives (RTO)
The maximum acceptable time that a system, application, or process can be down after a failure before it significantly impacts business operations.
Snapshot
It captures the full state of a system or device at the time the backup is complete. Common in VMs, they allow the machine state to be restored at the point in time that the snapshot was taken.
Images
Similar to snapshots, but most often they refer to a complete copy of a system or server, down to the bit level for the drive.
Common Choices for Backup Media
Magnetic Tape, Cloud backup options, Disks in a NAS device or SAN, Blue-Rays and DVDs, Flash media (Micro SD cards and USB thumb drives).
What are some considerations that come into play with cloud and off-site third-party backup options?
- Bandwidth requirements for both the backups and restoration time.
- Time to retrieve the files and cost to retrieve files.
- Reliability
- New Security models required for backups.
Scalability
An application’s or system’s ability to handle increasing workloads by adapting its resources. There are two primary types of scalability: Vertical Scalability and Horizontal Scalability.
Vertical Scalability
Requires a larger or more powerful system or device. Expanding the capacity of a single system by upgrading its hardware (e.g., increasing CPU, RAM, or storage).
Horizontal Scalability
Uses smaller systems or devices but adds more of them. Adding more instances or systems to distribute the workload, often used in cloud environments.
What are the three types of disaster recovery sites?
- Hot sites
- Warm sites
- Cold sites
These sites are chosen based on an organization’s Recovery Time Objective (RTO) and Recovery Point Objective (RPO).
Hot Sites
A fully operational backup site that mirrors the primary site in real time. It has all necessary hardware, software, and data, allowing for immediate failover with minimal downtime.
Warm Sites
A partially equipped backup site with essential infrastructure, but it requires some setup before becoming fully operational. Recovery time is moderate compared to a hot site. They balance costs and capabilities between hot sites and cold sites.
Cold Sites
A basic facility with minimal infrastructure, requiring significant time to set up and restore operations. It is the most cost-effective but has the longest recovery time.
What might a site restoration order include?
A list like the following:
- Restore network connectivity and bastion or a shell host.
- Restore network security devices (firewalls, IPS)
- Restore storage and database services.
- Restore critical operational services.
- Restore logging and monitoring service.
- Restore other services as possible.
