EC2 and Storage Flashcards

This is based on Section 5, 6 and 7

1
Q

What is the point of EC2 Instance Roles?

A

They allow for the instance to perform API calls on behalf of the instance to other AWS resources (i.e. Calls to IAM or S3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the difference between the On-Demand and Reserved Instance options?

A

On-Demand has no up-front costs, and is payed for by the second. You have full control over its lifecycle.

Reserved Instances are physically the same as On-Demand, however a billing discount is applied and must have certain attributes applied.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are Spot Fleets?

A

Spot fleets are a set of Spot Instances + (optional) On-Demand instances that are managed by AWS. The Spot Fleet will try to meet the target capacity with price constraints.

We must define multiple launch pools.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a storage optimized Instance?

A

Instances designed for workloads that require high, sequential read and write access to very large data sets.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the three Placement Group strategies?

A

Cluster: Clusters instances into a low-latency group in a single AZ, same hardware, low-latency

Spread: Spreads instances across underlying hardware

Partition: Spreads instances across many different partitions within an AZ, such that groups in one partition do not share underlying hardware with groups of instances in another partition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the max number of Partitions you can have per AZ for a Placement Group partition strategy?

A

Seven

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why would you create your own ENIs?

A

When instances are deleted, the default ENIs are deleted with them. With the creation of our own ENIs, we get to move them to instances we need them to be attached to and assign certain IP Addresses.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a Spot Instance?

A

Spot instances are instances that are ran when capacity is available and the spot price is lower than our maximum rates.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

You have an application performing big data analysis hosted on a fleet of EC2 instances. You want to ensure your EC2 instances have the highest networking performance while communicating with each other. Which EC2 Placement Group should you choose?

A

Cluster Placement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

You have a critical application hosted on a fleet of EC2 instances in which you want to achieve maximum availability when there’s an AZ failure. Which EC2 Placement Group should you choose?

A

Spread

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why would you use a Partition Placement strategy?

A

This is a good balance between High Performance and High Availability; we can have multiple instances in the same rack for High Performance and instances in other racks for High Availability.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

True or False: Elastic Network Interface (ENI) can be attached to EC2 instances in another AZ.

A

False. ENIs are bounded to a specific AZ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What storage type must be used to enable EC2 Hibernate?

A

EBS. The data persisting in RAM is migrated to EBS when the instance is hibernated. Only works with GP and Provisioned IOPS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does EBS attach to an Instance?

A

Through a network drive. This allows us to attach and detach

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

True or False: EBS can be bound across AZs?

A

False. If we want to move it across AZs, we need to create a snapshot and recreate it in another AZ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

If we want to move EBS volume across an AZ or Region, what can we do?

A

Create an EBS snapshot

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is an AMI?

A

Amazon Machine Image. It provides the information needed to launch an Instance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why would you use an EC2 Instance Store over an EBS volume?

A

The EC2 Instance Store will be more high performance than the EBS volume as it is physically located on the same disk

19
Q

What are the downsides on an EC2 Instance Store?

A

An Instance Store is lost under the following circumstances: underlying disk fails, instance stops, hibernated or terminates

We can also not transfer an Instance Store like we can an EBS Volume

20
Q

What volume types are provided by EBS?

A

General Purpose SSD, Provisioned IOPS SSD, Throughput Optimized HDD and Cold HDD

21
Q

If we need an EBS Volume type for intensive and frequent database workloads, which Volume type should we use?

A

Provisioned IOPS

22
Q

What two EBS Volume types can be Boot volumes?

A

General Purpose and Provisioned IOPS

23
Q

We want to attach an EBS to multiple instances. What can we do?

A

Use EBS Multi-Attach. Only works for Provisioned IOPS

24
Q

True or False: EFS can be in multi-AZ

A

True

25
Q

What is the difference between EFS and EBS

A

EBS will store data in the system in equal sized blocks. Allowing for faster retrieval.

EFS has an extra layer consisting of a file system to process before accessing the data. EFS is also multi-AZ by default.

26
Q

You have just terminated an EC2 instance in us-east-1a, and its attached EBS volume is now available. Your teammate tries to attach it to an EC2 instance in us-east-1b but he can’t. What is a possible cause for this?

A

EBS volumes are locked to an AZ

27
Q

You have launched an EC2 instance with two EBS volumes, Root volume type and the other EBS volume type to store the data. A month later you are planning to terminate the EC2 instance. What’s the default behavior that will happen to each EBS volume?

A

The Root volume type will be deleted and the other EBS volume type will not be deleted

28
Q

What is EBS Multi-Attach?

A

Attaches the same EBS volume to multiple EC2 instances in the same AZ

29
Q

You would like to encrypt an unencrypted EBS volume attached to your EC2 instance. What should you do?

A

Create an EBS snapshot of your EBS volume. Copy the snapshot and with encryption. Then, use the encrypted snapshot to create a new EBS volume

30
Q

You would like to have a high-performance local cache for your application hosted on an EC2 instance. You don’t mind losing the cache upon the termination of your EC2 instance. Which storage mechanism do you recommend as a Solutions Architect?

A

Instance Store

31
Q

You are running a high-performance database that requires an IOPS of 310,000 for its underlying storage. What do you recommend?

A

Use an EC2 Instance Store. EBS io2 has a max 256,000 IOPS and EBS io1 has a max 64,000 IOPS

32
Q

What are the two types of Spot Fleet requests?

A

Requests - If you configure the request type as request, it is only a one-time request. Spot Fleet does not attempt to replenish Spot Instances.

Maintain - Spot Fleet will attempt to maintain capacity by automatically replenishing any interrupted Spot Instances.

33
Q

What is a Spot Instance Pool

A

A Spot Instance Pool is a set of unused Instances with the same instance type (e.g. m5.large) and AZ

34
Q

Can we attach and detach root volumes from EC2 instances?

A

Yes, we can

https://serverfault.com/questions/588435/detatch-an-ebs-volume-from-one-instance-and-attach-to-another

35
Q

True or False: We can have multiple EBS volumes attached to a single EC2 instance

A

Yes

36
Q

What is EBS Snapshot Archive?

A

EBS Snapshot Archive moves a snapshot to an “archive tier” within S3 which is 75% cheaper. However, restoring from the snapshot takes within 24 to 72 hours

37
Q

Where do EBS snapshots reside?

A

In S3 storage

38
Q

How can we prevent accidental deletions of EBS snapshots?

A

We can setup rules to send deleted snapshots in a “recycle bin”. Recycle Bin is an AWS resource

39
Q

We need to recover an EBS snapshot with no latency when needed. What can we do?

A

Put it in Fast Snapshot Restore. Costs more money

40
Q

Which has better IOPS performance, Instance store or Block storage?

A

Instance Store usually has better IOPS performance; that’s because they are a hardware disk attached to the EC2 instance

41
Q

We need a high-performance storage option for an EC2 instance for cache and buffering data. What can we use?

A

EC2 Instance Store

42
Q

How many EC2 instances can be connected to one EBS Multi-Attach?

A

Up to 16

43
Q

What are EFS throughput modes?

A

Bursting: Throughput allowance is increased as workload increases (if credits are available). Depends on size of the file system

Elastic: Scales up or down to meet throughput needs; not dependent on credits

Provisioned: Users specify the level of throughput regardless of file system size or credits