EC2 Instance Storage

Question 1

What’s an EBS volume?

Answer 1

Network drive you can attach to your instances while they run, allows your instances to persist data even after termination

Question 2

If you have an EBS volume in one AZ, can you move it to a different AZ?

Answer 2

No

Question 3

What is an EBS snapshot?

Answer 3

Backup of your EBS volume at a point in time, can copy snapshots across AZ region

Question 4

EBS snapshot archive

Answer 4

Move a snapshot to an archive tier that is 75% cheaper

Question 5

Recycle Bin for EBS snapshots

Answer 5

Rules to retain deleted snapshots so you can recover them after accidental deletion (1 day to 1 year retention)

Question 6

Fast snapshot restore

Answer 6

Forces full initialisation of snapshot to have no latency on first use (costs lots of money)

Question 7

What is AMI?

Answer 7

Amazon Machine Image (customisation of EC2 instance, add your own software, config, OS )

Question 8

AMI process

Answer 8

• Start EC2 instance and customise
• Stop the instance for data integrity
• Build an AMI (this will create snapshots)
• Launch instances from other AMIs

Question 9

EC2 Instance store

Answer 9

• high performance hardware disk
• better I/O performance
• lose their storage if they’re stopped (ephemeral)

Question 10

What are EC2 instance stores good for?

Answer 10

• Buffer, cache, scratch data, temporary content
• high performance I/O

Question 11

How are EBS volume types characterised?

Answer 11

Size, throughput, IOPS

Question 12

Which EBS volume types can be used as boot volumes?

Answer 12

gp2/gp3 and io1/io2 block express

Question 13

General purpose SSD (gp2/gp3)

Answer 13

• cost effective storage, low latency
• system boot volumes
• gp3 is newer version (can independently set IOPS whereas gp2 its linked together)

Question 14

Provisioned IOPS (PIOPS) SSD (io1/io2)

Answer 14

• critical business applications with sustained IOPS performance
• great for database workloads sensitive to storage performance
• support EBS multi attach

Question 15

Hard Disk Drives (HDD) (st1/sc1)

Answer 15

• cannot be a boot volume
• st1 = throughput optimised HDD for big data, data warehouses, log processing
• sc1 = cold HDD for data infrequently accessed, low cost

Question 16

EBS multi attach

Answer 16

attach same EBS volume to multiple EC2 instances in the same AZ (only available io1/io2)

Question 17

EBS multi attach use case

Answer 17

achieve higher application in clustered linux applications (must be in same AZ, up to 16 instances)

Question 18

Amazon EFS (elastic file system)

Answer 18

Managed network file system that can be mounted on many EC2, works with EC2 instances in multi-AZ

Question 19

EFS use cases

Answer 19

Content management, web serving, data sharing, wordpress

Question 20

EFS performance classes

Answer 20

• EFS scale (scale up and down automatically)
• Performance mode
• Throughput mode

Question 21

EFS storage classes

Answer 21

• Standard (frequently accessed files)
• Infrequent access (cost to retrieve files)
• Archive (rarely accessed data)

Question 22

EBS volumes

Answer 22

• one instance (except multi attach io1/io2)
• locked to AZ level
• gp2: IO increases if disk size increases
• gp3/io1 can increase IO independently

Question 23

Migrate EBS volume across AZ

Answer 23

• take a snapshot
• restore snapshot to another AZ
• EBS backups use IO and you shouldn’t run them while application is handling traffic

Question 24

True or false? Root EBS volumes of instances get terminated by default if EC2 instance gets terminated

Answer 24

True but you can disable it