EC2 Flashcards
What is EC2?
EC2 is AWS’s VM in the cloud service
What are the 4 types of EC2 instances? (pricing)
1) On demand
2) Reserved
3) Spot
4) Dedicated hosts
What is EBS?
Elastic Block Store
A virtual disc in the cloud.
Is termination protection enabled by default?
No
What happens to the root EBS volume when an instance is terminated?
It is deleted
What happens to an additional EBS volume when an instance is terminated?
It is NOT deleted!
Can EBS volumes be encrypted?
Yes
What is a security group?
A security group is a virtual firewall that controls the traffic for one or more instances. You can assign a security group to instances or select a default security instance
What are the default inbound outbound traffic rules of a new security group?
All inbound traffic is blocked by default and all outbound traffic is allowed.
What do changes to a security group take effect?
Immediately
Can you have multiple security groups attached to an EC2 instance?
Yes
Are security groups stateful or stateless? and what does this mean?
They are stateful…. When you open a port you open for both outbound and inbound traffic
Can you block specific IP addresses in an security group?
No for that you will need to use an NACL
What is a NACL?
Network access control list.
An optional layer of security that acts as a firewall for controlling traffic in and out of one or more subnets
Can you specify deny rules in a security group?
No, you can only specify allow rules.
Name 2 SSD based EBS volume types…
1) General purpose SSD- gp2
2) Provisioned IOPS SSD- i01
Name 3 magnetic based EBS volume types…
1) Throughput optimised- st1
2) Cold HDD- sc1
3) Magnetic
What is the use case for a gp2 EBS volume?
Most workloads
Max IOPS= 16,000
Volume size= 1GB-16TB
What is the use case for a io1 EBS volume?
e.g. a EC2 based database that are mission critical!
Max IOPS= 64,000
Volume size= 1GB-16TB
What does IOPS stand for?
Inputs/outputs per second
What is the use case for a st1 volume?
Throughput intensive big data workloads
Max IOPS= 500
Vol size=500GB-16TB
What is the use case for a sc1?
File severs
Max IOPS= 250
Vol size= 500GB-16TB
What is the use case for Magnetic?
Workloads that are infrequently accessed
Max IOPS= 40-200
Vol size= 16GB-1TB
Can you have a EBS in a different AZ to an the EC2 instance interacting with it?
No, the EC2 instance and EBS volume must be the same AZ
What is snapshot?
A snapshot is a copy of an EBS volume. They exist on S3. These are point in time copies of volumes. They are incremental.
What should you do to take a snapshot of a root EBS volume?
Stop the EC2 instance before creating the snapshot
Can you create AMI’s from volumes and snapshots?
Yes
Can you change EBS volume sizes on the fly? including storage type?
Yes