Planning for the Worst Flashcards
Power Surge
An unexpected increase in the amount of voltage provided
Power Spike
A short transient in voltage that can be due to a short circuit, tripped circuit breaker, power outage, or lightning strike
Power Sag
An unexpected decrease in the amount of voltage provided
Brownout
Occurs when the voltage drops low enough that it typically causes the lights to dim and can cause a computer to shut off
Blackout
Occurs when there is a total loss of power for a prolonged period
RAID Versions
RAID 0 = Disk striping
RAID 1 = Disk mirroring
RAID 5 = Disk striping w/parity
RAID 6 = Disk striping w/double parity
RAID 10 = Stripes two mirrored RAIDs
RAID 0+1 = Mirrors two striped RAIDs
Fault-Resistant RAID
Protects against the loss of the array’s data if a single disk fails (RAID 1 or RAID 5)
Fault-Tolerant RAID
Protects against the loss of the array’s data if a single component fails
(RAID 1, RAID 5, RAID 6)
Disaster-Tolerant RAID
Provides two independent zones with full access to the data (RAID 10)
Server Redundancy: Cluster
Two or more servers working together to perform a particular job function
Failover Cluster
A secondary server can take over the function when the primary one fails
Load-Balancing Cluster
Servers are clustered in order to share resources such as CPU, RAM, and hard disks
Redundant Sites
Hot Site:
A near duplicate of the original site of the organization that can be up and running within minutes
Warm Site:
A site that has computers, phones, and servers but they might require some configuration before users can start working
Cold Site:
A site that has tables, chairs, bathrooms, and possibly some technical items like phones and network cabling
10 Tape Rotation
Each tape is used once per day for two weeks and then the entire set is reused
Grandfather-Father-Son
Three sets of backup tapes are defined as the son (daily), the father (weekly), and the grandfather (monthly)
Towers of Hanoi
Three sets of backup tapes (like the grandfather-father-son) that are rotated in a more complex system
Disaster Recovery Plan Attributes
Contact Information
Impact Determination
Recovery Plan
Business Continuity Plan (BCP)
Copies of Agreements
Disaster Recovery Exercises
List of Critical Systems and Data
Business Impact Analysis (BIA)
A systematic activity that identifies organizational risks and determines their effect on ongoing, mission critical operations
Business impact analysis is governed by metrics that express system availability
Maximum Tolerable Downtime (MTD)
The longest period of time a business can be inoperable without causing irrevocable business failure
Each business process can have its own MTD, such as a range of minutes to hours for critical functions, 24 hours for urgent functions, or up to 7 days for normal functions
MTD sets the upper limit on the recovery time that system and asset owners need to resume operations
RTO
Recovery Time Objective:
The duration of time and a service level within which a business process must be restored after a disaster in order to avoid unacceptable consequences associated with a break in continuity.
WRT
Work Recovery Time:
The length of time in addition to the RTO of individual systems to perform reintegration and testing of a restored or upgraded system following an event
RPO
Recovery Point Objective:
The longest period of time that an organization can tolerate lost data being unrecoverable
Recovery Point Objective (RPO) is focused on how long can you be without your data
MTTR
Mean Time to Repair:
Measures the average time it takes to repair a network device when it breaks
MTBF
Mean Time Between Failures:
Measures the average time between failures of a device
Pulverizing & Shredding
Heavy machinery; complete destruction
Load Balancing: Scheduling
Round-robin
Each server is selected in turn
Weighted round-robin
Prioritize one server over another
Dynamic round-robin
Monitor server load & distribute to the server with lowest use
Active/active
All servers operating, if one fails, operation continues normally
