EC2

Question 1

EBS: What are the cheapest storage options and what things should you consider? Whats the cheapest SSD option?

Answer 1

> If you need CHEAP, use ST1 or SC1 (HDD based)
If you need throughput - i.e. streaming, use ST1
You CANNOT use HDD-based volumes as boot volumes
If too slow, upgrade to SSD-based GP3 (or legacy GP2)

Question 2

EBS: Max IOPS of GP3?

Answer 2

16,000 IOPS.
GP2/GP3 is SSD based and is faster than ST1/SC1.
If you need more IOPS, advance to IO1/IO2/IO BlockExpress

Question 3

EBS: IO-1 / IO-2 max IOPS?

Answer 3

• IO is the Fastest EBS option.
• IO1/IO2 Can deliver between 16,000 and 64,000 IOPS
• IO2 BlockExpress can deliver up to 256,000 IOPS.
• If you don’t need 16,000 IOPS, downgrade to GP3.
• If you need MORE throughput without the persistence & resiliency, use Instance Store volumes.

Question 4

EBS: Per-Instance Performance Limitations

Answer 4

260,000 IOPS
Note that you’re going to need more than one volume to saturate these per-instance performance levels

Question 5

EBS: What are Snapshots and what can you do with them?

Answer 5

• You can take a snapshot into s3 and use that snapshot to create a new volume in a different AZ.
• You can also copy a snapshot to a different region and create a volume from the snapshot.

Question 6

EBS: Resiliency Level?

Answer 6

EBS has resilience within an AZ

Question 7

EBS: Charges?

Answer 7

Based on per GB per month

Question 8

Instance Store: Benefits, Details?

Answer 8

• Provides TEMPORARY block-level storage for your EC2 instance.
• Local on EC2 host: disks are physically attached to the host computer
• Fastest storage option AWS can provide

Question 9

Instance Store: Max Throughput?

Answer 9

> With a D3 instance, you can achieve 4.6 GB/s of throughput.
With an I3 instance, you can achieve 16 GB/s of throughput.

Question 10

EBS: Details?

Answer 10

• EBS is a Network Attached Storage
• EBS is highly resilient and is separate from the EC2 host
• Volumes have a block number
• Can be encrypted using KMS

Question 11

EC2: What are the following common instance types?
C, R, I, D, G, P

Answer 11

C: Compute
R: RAM
I: IO
D: Dense Storage
G: GPU
P: Parallel processing

Question 12

In which situations can you connect network interfaces or EBS storage located in one AZ to an EC2 instance located in a different AZ?

Answer 12

Never. This is impossible since EC2 instances live exclusively within one AZ.

Question 13

What properties are attached to ENIs?

Answer 13

> Security Groups (these are not attached directly to the EC2 instance)
Mac Address
Primary IPv4 Private IP (from within the subnet)
0 or more secondary private IPs
0 or 1 Public IPv4 address
1 elastic IP per private IPv4 address
0 or more IPv6 addresses

Question 14

ENIs: How to move software licenses between EC2 instances?

Answer 14

> Attach your licenses to a secondary ENI, since you can later detach and move the secondary ENI to a different instance.
Note that software licenses are typically tied to the MAC address, which comes from the ENI.

Question 15

ENIs: Do public DNS names get resolved to the public or private IP for an ENI?

Answer 15

Trick question!
Within a VPC, the public DNS name resolves to the private IP.
Outside the VPC, the public DNS name resolves to the public IP.