EC2

Question 1

Instance pricing models

Answer 1

On Demand, Spot, Reserved, Dedicated Hosts

Question 2

If you terminate spot instance

Answer 2

you pay for the hour. If AWS terminates it, you are not charged for the hour

Question 3

Instance types

Answer 3

DRMCGIFTPX

Question 4

EBS types

Answer 4

SSD, General Purpose - GP2 (up to 10k IOPS)
SSD, Provisioned IOPS - IO1 (> 10k IOPS)
HDD, Throughput Optimized - ST1 (frequently accessed workloads)
HDD, Cold - SC1 (less frequently accessed data)
HDD, Magnetic Standard (cheap, infrequently accessed storage)

Question 5

Can you mount 1 EBS volume to multiple EC2 instances?

Answer 5

No, use EFS instead

Question 6

Termination protection

Answer 6

is turned off by default, you must turn it on

Question 7

On an EBS-backed instance, the default action is for the root EBS volume

Answer 7

to be deleted when the instance is terminated

Question 8

Can root volumes be encrypted by default?

Answer 8

No, you need a third party tool to encrypt the volume. Additional volumes can be encrypted

Question 9

Volumes exist on

Answer 9

EBS. virtual hard disk

Question 10

Snapshots exist on

Answer 10

S3

Question 11

Can you take a snapshot of a volume?

Answer 11

Yes, this will store that volume on S3

Question 12

What are snapshots?

Answer 12

point in time copies of Volumes

Question 13

Snapshots are incremental, so

Answer 13

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

Question 14

First snapshots

Answer 14

may take some time to create

Question 15

Snapshots of encrypted volumes

Answer 15

are encrypted automatically

Question 16

Volumes restored from encrypted snapshots

Answer 16

are encrypted automatically

Question 17

Can you share snapshots?

Answer 17

Yes if they are unencrypted. these snapshots can be shared with other AWS accounts or made public

Question 18

to create a snapshot for EBS volumes that serve as root devices,

Answer 18

you should stop the instance before taking the snapshot

Question 19

Instance store volumes are sometimes called

Answer 19

ephemeral storage

Question 20

Can instance store volumes be stopped?

Answer 20

No, if the underlying host fails, you will lose your data

Question 21

Can EBS volumes be stopped?

Answer 21

Yes, you will not lose data if it is stopped

Question 22

Can you reboot volumes?

Answer 22

Yes for both, you will not lose data

Question 23

By default, both root volumes

Answer 23

will be deleted on termination, but you can tell AWS to keep the root EBS volume

Question 24

How to take snapshot of a raid array?

Answer 24

take application consistent snapshot to prevent excluding data. stop the app from writing to the disk + flush all caches to the disk. freeze file system or unmount raid array or shut down associated instance

Question 25

Are AMIs global or regional?

Answer 25

Regional. You can only launch an AMI from the region in which it is stored. However you can copy AMIs to other regions using the console, command line or API

Question 26

CloudWatch

Answer 26

standard=5 mins, detailed=1 min

Question 27

CloudWatch is for

Answer 27

performance monitoring

Question 28

CloudTrail is for

Answer 28

auditing

Question 29

With CloudWatch you can do

Answer 29

Dashboards, Alarms, Events, Logs

Question 30

Which is more secure, Roles or storing access key ID/secret access key on instances?

Answer 30

Roles, they are also easier to manage

Question 31

Can roles be assigned to an EC2 instance after it's created?

Answer 31

Yes but only using the command line

Question 32

Are roles universal?

Answer 32

Yes

Question 33

Instance metadata

Answer 33

used to get info about instance (e.g. public ip) | curl http://169.254.169.254/latest/meta-data/

Question 34

Is there user data for an instance?

Answer 34

No

Question 35

EFS features

Answer 35

supports NFSv4, only pay for storage you use, can scale up to petabytes, can support thousands of concurrent NFS connections, data is stored across multiple AZs in a region

Question 36

Consistency of EFS

Answer 36

read after write

Question 37

Lambda

Answer 37

compute service where you upload your code and create Lambda function. AWS takes care of provisioning and managing servers you use

Question 38

Use Lambda as

Answer 38

event-driven compute service where Lambda runs your code in response to events, as compute service to run your code in response to HTTP requests using API Gateway or API calls made using AWS SDKs