EC2

Question 1

What is EC2?

Answer 1

Elastic Compute Cloud, a web service that provide resizable compute capacity in the cloud. You only pay for the capacity you use

Question 2

EC2 Options

Answer 2

On Demand
Reserved
Spot

Question 3

On Demand Pricing Structure

Answer 3

fixed rate by the hour with no commitment

Question 4

Reserved Pricing Structure

Answer 4

you get a capacity reservation with a significant discount on hourly charge. 1 or 3 year terms

Question 5

Spot

Answer 5

enables on to bid whatever price you want for instance capacity

Question 6

On Demand uses cases include

Answer 6

Users wanting low cost and flexibility without upfront payment or long-term commitment

App with short-term, spiky or unpredictable workloads that cannot be interrupted

Apps being developed/tested

Question 7

Reserved uses cases include

Answer 7

Apps with steady state or predictable usage

Apps that require reserved capacity

Users able to make upfront payment to reduce their total computing costs

Question 8

Spot

Answer 8

Apps that have flexible start and end times

Apps that are only feasible at very low compute prices

Users with urgent computing needs for large amounts of additional capacity

Question 9

EC2 instance types include:

Answer 9

T2, M3/4, C3/4, R3, G2, I2, D2 (T MaC RiGID)

Question 10

What is EBS?

Answer 10

Elastic Block Storage. It is basically a disk in the cloud that can be attached to only one EC2 instance.

Question 11

EBS volume types include:

Answer 11

General purpose SSD (GP2)
Provisioned IOPS SSD (IO1)
Magnetic (Standard)

Question 12

General purpose SSD (GP2)

Answer 12

99.999% availability
Ratio of 3 IOPS per GB with up to 10,000 IOPS
Ability to burst up to 3000 IOPS for short periods for volumes under 1Gib

Question 13

IOPS

Answer 13

Input/Output per second

Question 14

Provisioned IOPS SSD (IO1)

Answer 14

Designed for I/O intensive applications. Use if you need more than 10,000 IOPS

Question 15

Magnetic

Answer 15

Traditional disk storage - ideal for infrequently accessed data and for low-cost storage.

Question 16

True or False. Termination protection for EC2 instances are turned on by default.

Answer 16

False. It is on turned on.

Question 17

What is the default action for an EBS-backed instance when the instance is terminated?

Answer 17

The root EBS volume is deleted.

Question 18

True or False. Root volumes cannot be encypted by default.

Answer 18

True, you need a third party tool to encrypt the root volume. However, additional volumes can be encrypted.

Question 19

What is a volume and where do they exist?

Answer 19

a virtual hard disk on EBS

Question 20

What is a snapshot and where do they exist?

Answer 20

Snapshots are point in time copies of volumes and exist on S3

Question 21

Snapshots are incremental meaning…

Answer 21

That only the blocks that have changed since the last snapshot are moved to S3.

Question 22

Can snapshots be shared?

Answer 22

Yes, only if they are unencrypted.

Question 23

Under what conditions should you take a snapshot of a root device?

Answer 23

After stopping the instance.

Question 24

How can a snapshot of a RAID array be taken?

Answer 24

By either:

1. Freezing the file system
2. Unmounting the RAID array
3. Shutting down the associated EC2 instance

Question 25

What is an AMI?

Answer 25

Amazon Machine Image is a template which provides the information required to launch a virtual server in the cloud.

Question 26

What composes the AMI?

Answer 26

1. A template for the root volume for the instance 2. Launch permissions that control which AWS accounts can use the AMI to launch instances 3. A block device mapping that specifies the volumes to attach to the instance when it's launched.

Question 27

All AMIs are categorized as either backed by...

Answer 27

Amazon EBS or instance store

Question 28

For EBS volumes, the root device for an instance launched from the AMI is...

Answer 28

An Amazon EBS volume created from an Amazon EBS snapshot.

Question 29

For instance store volumes, the root device for an instance launched from the AMI is..

Answer 29

An instance store volume created from a template stored in Amazon S3

Question 30

What another name for instance store volumes?

Answer 30

Ephemeral storage

Question 31

Can instance store volumes be stopped?

Answer 31

No. If the underlying host fails you lose all data

Question 32

What happens to the EBS and instance store root volumes upon termination?

Answer 32

By default, the root volume will be terminated; however with EBS volumes, you can tell AWS to keep the root device volume

Question 33

True or false. Elastic Load Balancers have their own IP address.

Answer 33

False. They have their own DNS name. They are never given an IP address

Question 34

In Cloud Watch, what are the standard and detailed monitoring times?

Answer 34

5 minutes for standard, 1 minute for detailed

Question 35

What are some features of cloudwatch?

Answer 35

Dashboards - see what's happening Alarms - notify you of threshold hits Events - help you to respond to state changes Logging

Question 36

Can you assign a role to an existing EC2 instance?

Answer 36

No. Only when the instance is being provisioned.

Question 37

What some of the advantages of using roles to access and EC2 instance?

Answer 37

1. more secure than storing the access key and secret access key on individual EC2 instances 2. roles are universal which means you can use them in any region 3. roles are easier to manage

Question 38

What is the metadata URL?

Answer 38

http://169.254.169.254/latest/meta-data/