2.5 Cybersecurity Resilience Flashcards
the practice of keeping data in two or more places within a database or data storage system. [this] ensures an organization can provide continued operations or services in the event something happens to its data -- for example, in the case of data corruption or data loss. • Duplicate parts of the system – If a part fails, the redundant part can be used • Maintain uptime – The organization continues to function • No hardware failure – Servers keep running • No software failure – Services always available • No system failure – Network performing optimally
(Disk) Redundancy
• Bad things can happen in a local area
– Hurricanes, tornadoes, flooding,
• Disperse technologies to different geographies
– Use multiple data centers
– In different locations
• Data centers might be part of the normal operations
– East coast and west coast operations centers
• May be part of a disaster recovery center
– If Florida gets hit, fire up the Denver data center
Geographic dispersal
• Multipath* I/O (Input/Output) - a fault-tolerance and performance enhancement technique in which more than one physical path exists between the server and its storage devices through the buses, controllers, and switches connecting them.
– Especially useful for network-based storage subsystems
– Multiple Fibre Channel interfaces with multiple switches
• RAID* - Redundant Array of Independent Disks - a way of storing the same data in different places on multiple hard disks or solid-state drives (SSDs) to protect data in the case of a drive failure. There are different RAID levels, however, and not all have the goal of providing redundancy.
• Multiple drives create redundancy
– Many different designs and implementations
Disk redundancy
the process of distributing network traffic across multiple servers. This ensures no single server bears too much demand. By spreading the work evenly, [this] improves application responsiveness. It also increases availability of applications and websites for users.
• Some servers are active - Others are on standby
• If an active server fails, the passive server takes its place
Load balancing
allows you to combine multiple physical network adapters into a virtual NIC, which will then be presented to the OS as a single NIC. All of the traffic being sent from the OS will pass through the virtual NIC and be load-balanced across the assigned physical network connections. • Load Balancing / Fail Over (LBFO) – Aggregate bandwidth, redundant paths – Becomes more important in the virtual world • Multiple network adapters – Looks like a single adapter – Integrate with switches • NICs talk to each other – Usually multicast instead of broadcast – Fails over when a NIC doesn’t respond
NIC teaming
a device that allows a computer to keep running for at least a short time when incoming power is interrupted. – Short-term backup power – Blackouts, brownouts, surges • UPS types – Offline/Standby UPS – Line-interactive UPS – On-line/Double-conversion UPS • Features – Auto shutdown, battery capacity, outlets, phone line suppression
UPS - Uninterruptible Power Supply
a routine that can be used to control the iteration behavior of a loop. All generators are also iterators. • Long-term power backup – Fuel storage required • Power an entire building – Some power outlets may be marked as generator-powered • It may take a few minutes to get the generator up to speed – Use a battery UPS while the generator is starting
Generators
a regular direct current power supply. It can provide a positive as well as negative voltage. It ensures stable power supply to the device as well as it helps to prevent system damage. Many electronic circuits require a source of DC power.
• Redundancy
– Internal server power supplies
– External power circuits
• Each power supply can handle 100% of the load
– Would normally run at 50% of the load
• Hot-swappable
– Replace a faulty power supply without powering down
Dual-power supplies
a device for controlling electrical power in a data center. The most basic [this] are large power strips without surge protection. They are designed to provide standard electrical outlets for data center equipment and have no monitoring or remote access capabilities. • Provide multiple power outlets – Usually in a rack • Often include monitoring and control – Manage power capacity – Enable or disable individual outlets
Power distribution units (PDUs)
a service where a centralized repository of stored or archived data is duplicated to another centralized data repository in real-time. [this] replication provides an extra measure of redundancy in case a main storage system fails.
• Share data between different devices
– If one device fails, you can still work with the data
– VERY fast recovery times compared to
traditional backups
• [this]
– Specialized high-performance network of
storage devices
• [this]-to-[this] replication
– Duplicate data from one data center to another
• [this] snapshot
– Create a state of data based on a point in time
– Copy that state to other [this]
Storage area network (SAN) replication
a process used by information technology (IT) professionals to create backup versions of virtual machines (VMs) The backup can be kept and used to restore the machine in the event that its data is corrupted or lost.
• [this]
– Maintain one VM, replicate to all others
– The virtual machine is really just one big file
2.5 - Replication
• Consistent service offering
– Maintain copies anywhere in the world
• Recover from a replicated copy
– Provides a backup if needed
• Efficient copying
– Only replicates the data that has changed
VM replication
On premises vs. cloud redundancy
• Speed
– Local devices are connect over very fast networks
– Cloud connections are almost always slower
• Money
– Purchasing your own storage is an expensive
capital investment
– Cloud costs have a low entry point and can scale
• Security
– Local data is private
– Data stored in the cloud requires additional
security controls
On premises vs. cloud redundancy
• The archive attribute – Set when a file is modified • Full - Everything – You’ll want this one first • Incremental – All files changed since the last incremental backup • Differential – All files changed since the last full backup
Backup Types
a backup type that only copies data that has been changed or created since the previous backup activity was conducted. [this] approach is used when the amount of data that has to be protected is too voluminous to do a full backup of that data every day. • A full backup is taken first • Subsequent backups contain data changed since the last full backup and last incremental backup – These are usually smaller than the full backup • A restoration requires the full backup and all of the incremental backups
Incremental Backup
a data backup that copies all of the files that have changed since the last full backup was performed. This includes any data that has been created, updated or altered in any way and does not copy all of the data every time. • A full backup is taken first • Subsequent backups contain data changed since the last full backup – These usually grow larger as data is changed • A restoration requires the full backup and the last differential backup
Differential Backup
