Section 6: EC2 Instance Storage

Question 1

EBS (Elastic Block Store) Volume

Answer 1

A network drive you can attach to your instances while they run. Allows instances to persist data, even after termination. Can only be mounted to one instance at a time. It’s bound to a specific AZ. Can use a snapshot to move a volume to a different AZ.

It’s a network drive, so there might be some latency. Can be detached from an EC2 instance and attached to another one quickly.

Must provision capacity (size in GB’s, and IOPS) in advance.

Delete on Termination is default for the root EBS volume, but not for other attached EBS volumes.

Only gp2/gp3 and io1/io2 Block Express can be used as boot volumes.

Question 2

EBS Snapshots

Answer 2

Can make backups (snapshots) of your EBS volume at a point in time.

Doesn’t need to detach volume to do snapshot, but recommended.

Can copy snapshots across AZ or Region.

Question 3

EBS Snapshot Archive

Answer 3

Move a snapshot to an “archive tier” that’s 75% cheaper.

Takes within 24-72 hours for restoring the archive.

Question 4

Recycle Bin for EBS Snapshots

Answer 4

Setup rules to retain deleted snapshots so you can recover them after an accidental deletion. Can retain from 1 day to 1 year.

Question 5

Fast Snapshot Restore (FSR)

Answer 5

Force full initialisation of snapshot to have no latency on the first use. It’s very expensive.

Question 6

AMI (Amazon Machine Image)

Answer 6

It’s a customisation of an EC2 instance.

Can add your own software, configuration, OS, monitoring, etc.

Faster boot/configuration time because all your software is pre-packaged.

Built of a specific Region, and can be copied across Regions.

There are AWS-provided AMI’s, AWS Marketplace AMI, and your own AMI’s.

Need to start an EC2 instance and customise it, then stop the instance, build an AMI, then launch instances from other AMI’s.

Question 7

EC2 Instance Store

Answer 7

A high-performance hardware disk with better I/O performance, but loses their storage if they’re stopped.

Good for buffer/cache/scratch data/temporary content.

There’s risk of data loss if the hardware fails, so need to backup and replicate.

Question 8

EBS Volume Type: gp2/gp3 (SSD)

Answer 8

General purpose SSD volume that balances price and performance for a wide variety of workloads.

gp2
- Small gp2 volumes can burst IOPS to 3,000
- Size of the volume nad IOPS are linked, max IOPS is 16,000
- 3 IOPS per GB, means at 5,334 GB we are at the max IOPS

gp3
- Baseline of 3,000 IOPS and throughput of 125 MB/s
- Can increase IOPS up to 16,000 and throughput up to 1,000 MB/s independently

Question 9

EBS Volume Type: io1/io2 Block Express (SSD)

Answer 9

Highest-performance SSD volume for mission-critical low-latency or high-throughput workloads.

Question 10

EBS Volume Type: st1 (HDD)

Answer 10

Low cost HDD volume designed for frequently accessed, throughput-intensive workloads.

Question 11

EBS Volume Type: sc1 (HDD)

Answer 11

Lowest cost HDD volume designed for less frequently accessed workloads.

Question 12

General Purpose SSD

Answer 12

Cost effective storage, low-latency.

Great for system boot volumes, virtual desktops, development, and test environments
1 GB to 16 TB

Question 13

Provisioned IOPS (PIOPS) SSD

Answer 13

Mainly for critical business applications with sustained IOPS performance, or applications that need more than 16,000 IOPS. Great for database workloads.

io1 (4 GB - 16 TB)
- Max PIOPS: 64,000 for Nitro EC2 instances & 32,000 for other
- Can increase PIOPS independently from storage size

io2 Block express
- Sub-millisecond latency
- Max PIOPS: 256,000 with an IOPS:GB ratio of 1,000:1

Supports EBS Multi-attach

Question 14

Hard Disk Drivers (HDD)

Answer 14

Can’t be a boot volume.

125 GB to 16TB

Throughput Optimized HDD (st1)
- Big Data, Data Warehouses, Log Processing
- Max throughput 500 MB/s - max IOPS 500

Cold HDD (sc1)
- For data that’s infrequently accessed
- Scenarios where lowest cost is important
- Max throughput 250 MB/s - max IOPS 250

Question 15

EBS Multi-Attach

Answer 15

Can attach the same EBS volume to multiple EC2 instances in the same AZ. Only available for the io1/io2 family.

Each instance has full read & write permissions to the high-performance volume.

Great for achieving higher application availability in clustered Linux applications, and when applications must manage concurrent write operations.

Must use a file system that’s cluster-aware. Up.

Can attach up to 16 EC2 instances at a time.

Question 16

EFS - Elastic File System

Answer 16

A managed NFS (network file system) that can be mounted on many EC2 instances. Can work with EC2 instances in multi-AZ’s. Highly available, scalable, expensive (3x gp2), pay per use.

Great for content management, web serving, data sharing, Wordpress.

It uses NFSv4.1 protocol and security group to control access to EFS. There’s encryption at rest using KMS.

Question 17

EFS - Performance & Storage Classes

Answer 17

EFS Scale:
- Thousands of concurrent NFS clients, 10 GB+ /s throughput
- Grow to Petabyte-scale network file system, automatically

Performance Mode (set at EFS creation time):
- General Purpose (default) - latency-sensitive use cases (web server, CMS, etc…)
- Max I/O - higher latency, throughput, highly parallel (big data, media processing)

Throughput Mode:
- Bursting - 1 TB = 50MB/s + burst of up to 100MB/s
- Provisioned - set your throughput regardless of storage size, ex: 1 GB/s for 1 TB storage
- Elastic - automatically scales throughput up or down based on your workloads; up to 3 GB/s for reads and 1 GB/s for writes; used for unpredictable workloads

Question 18

EFS Storage Tiers - Standard

Answer 18

For frequently accessed files.

Multi-AZ, great for production.

Question 19

EFS Storage Tiers - Infrequenty Access

Answer 19

Cost to retrieve files, lower price to store.

Question 20

EFS Storage Tiers - Archive

Answer 20

Rarely access data (few times each year), 50% cheaper

Question 21

Lifecycle Policy

Answer 21

Can be used to move files between storage tiers.

Question 22

EFS Storage Tiers Availability and Durability

Answer 22

Standard: Multi-AZ, great for production.

One Zone: One AZ, great for development, backup enabled by default, compatible with IA (EFS One Zone-IA).