CH28 Planning for the Worst

Question 1

What is Surge?

Answer 1

unexpected increase in the amount of voltage provided. A little bit of increase in power (going from 120 volts to 124 or 135)

Question 2

What is Spike?

Answer 2

a short transient in voltage that can be due to a short circuit, tripped circuit breaker, power outage, or lightning strike. (jump from 120 volts to 140 or more)

Question 3

What is Sags ?

Answer 3

unexpected decrease in the amount of voltage provided. Lasts short period of time and wouldn’t impact computer to go out of power

Question 4

What is Brownouts ?

Answer 4

Occurs when the voltage drops low enough that it typically causes the lights to dim and can cause a computer to shut off. (dropping from 120 volts to 90 or 80)

Question 5

What is Blackouts ?

Answer 5

When there is a total loss of power for a prolonged period. When they come back from blackout conditions, you get a spike in power that occurs which can damage your computer

Question 6

What is Uninterruptible Power Supply (UPS) ?

Answer 6

Combines the functionality of a surge protector with that of a battery backup

Question 7

What is Portable gas-engine generators ?

Answer 7

Of three types of backup generators, it is the least expensive to run. Uses gasoline or solar power. Needs to be started manually.

Question 8

What is Permanently installed generators ?

Answer 8

Compared to 2 other types of backup generators, it is much bigger, much more expensive, much more complex to install. They’re always there. Runs on natural gas, propane, or diesel fuel.

Question 9

What is Battery-inverter generator?

Answer 9

Backup generator that is based on lead acid batteries. Very quiet and they require very little user interaction. Good for environments that require a low amount of wattage or are the victims of short power outrages only

Question 10

What is RAID?

Answer 10

Redundant Array of Independent Disks (RAID) – allows the combination of multiple physical hard disks into a single logical hard disk drive that is recognized by the operating system.

For the exam: You need to know about RAID types : RAID 0, RAID 1, RAID 5, RAID 6, and RAID 10.

Question 11

What is RAID 0 ?

Answer 11

provides data striping across multiple disks to increase performance.

Use RAID 0 when you need performance but you don’t care about fault tolerance.

You need at least 2 disks to work in tandem with each other.

A1 A2
A3 A4
A5 A6
A7 A8

Question 12

What is RAID 1 ?

Answer 12

provides redundancy by mirroring the data identically on two hard disks. Requires 2 disk

A1 A1
A2 A2
A3 A3
A4 A4

Question 13

What is RAID 5 ?

Answer 13

Provides redundancy by striping data and parity data across the disk drives

A1 A2 A3 Ap
B1 B2 Bp B3
C1 Cp C2 C3
Dp D1 D2 D3

Question 14

What is RAID 6 ?

Answer 14

Provides redundancy by striping and double parity data across the disk drives. Need at least 4 physical disks

A1 A2 A3 Ap A1
B1 B2 Bp B1 B3
C1 Cp Cq C2 C3
Dp Dq D1 D2 D3
Eq E1 E2 E3 Ep

Question 15

What is RAID 10 ?

Answer 15

Creates a striped RAID of 2 mirrored RAIDS (combines RAID 1 & RAID 0). Need at least 4 disks. It’s going to provide you with a redundant mirror of striped drives and it is fault-tolerant. Two independent zones, with full access to the data at all times

A1 A1 A2 A2
A3 A3 A4 A4
A5 A5 A6 A6
A7 A7 A8 A8

Question 16

What are the 3 categories of RAIDs?

Answer 16

1. Fault-resistant – protects against the loss of the array’s data if a single disk fails (RAID 1 or RAID 5)
2. Fault-tolerant – protects against the loss of the array’s data if a single component fails (RAID 1, RAID 5, RAID 6)
3. Disaster-tolerant – Provides two independent zones with full access to the data (RAID 10)

Question 17

What is RAID 01?

Answer 17

a striped array made up of two mirrored RAID 1. It is also disaster tolerant

Question 18

What is Network Redundancy ?

Answer 18

to make network connections available, servers often have two or more network interface parts, and they can operate as a pair or in a load balancing configuration

Question 19

What is Cluster ?

Answer 19

two or more servers working together to perform a particular job function

Question 20

What is Failover Cluster?

Answer 20

a secondary server can take over the function when the primary one fails

Question 21

What is Load-balancing Cluster?

Answer 21

Servers are clustered in order to share resources such as CPU, RAM, and hard disks

Question 22

What are the 3 categories of redundant sites ?

Answer 22

1. Hot Site – a near duplicate of the original site of the organization that can be up and running within minutes
2. Warm Site – a site that has computers, phones, and servers, but they might require some configuration before users can start working
3. Cold Site – has tables, chairs, bathrooms, and possibly some technical items like phones and network cabling

Question 23

What is a Full backups ?

Answer 23

all the contents of a drive are backed up

Question 24

What is an Incremental Backups?

Answer 24

only conducts a backup of the contents of a drive that have been changed since the last full or incremental backup

Full back up on Sunday
Incremental backup Monday
Incremental backup Tuesday
Wednesday failure.
To restore, I will need to restore Full back up on Sunday and restore Monday backup, and then Tuesday backup

Incremental backup takes less time to create but longer to restore.

Question 25

What is a Differential Backups ?

Answer 25

only conducts a backup of the contents of a drive that has changed since the last full backup. Full back up on Sunday Differential backup Monday Differential backup Tuesday Wednesday failure. To restore, I will need to restore Full back up on Sunday and restore Tuesday backup only Differential backup takes more time to create but quicker to restore

Question 26

What are 3 types of tape rotation schemes?

Answer 26

1. 10 tap rotation – each tape is used once per day for two weeks and then the entire set is reused. 2. Grandfather-father-son rotation – three sets of backup tapes are defined as the son (daily), the father (weekly), and the grandfather (monthly) 3. Towers of Hanoi rotation – three sets of backup tapes that are rotated in a more complex system.

Question 27

What is Snapshot Backup?

Answer 27

Type of backup primarily used to capture the entire operating system image including all applications and data. It is also commonly used with virtualized systems

Question 28

What is Disaster Recovery Plan?

Answer 28

the development of an organized and in-depth plan for problems that could affect the access of data or the organization’s building Disaster Recover Plan (DRP) should be written down : Contact information, impact determination, recovery plan, business continuity plan (BCP), Copies of agreements, disaster recovery exercises, list of critical systems and data

Question 29

What is Business Impact Analysis (BIA)?

Answer 29

a systematic activity that identifies organizational risks and determines the effect on ongoing, mission critical operations. It is governed by metrics that express system availability. (90% up time? 100% up time?)

Question 30

What is MTD?

Answer 30

MTD = Maximum Tolerable Downtime 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.

Question 31

What is RTO?

Answer 31

RTO = Recovery Time Objectives The length of time it takes after an event to resume normal business operations and activities

Question 32

What is WRT?

Answer 32

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.

Question 33

What is RPO?

Answer 33

RPO = Recovery Point Objective (RPO) longest period of time that an organization can tolerate lost data being unrecoverable. It is focused on how long you can be without your data

Question 34

What is MTTR?

Answer 34

MTTR = Mean Time to Repair measure the average time it takes to repair a network device when it breaks.

Question 35

What is MTBF

Answer 35

MTBF = Mean Time Between Failures Measures the average time between failures of a device