Virtual Machines in AWS
- Called as EC2
Dependencies for EC2 instances on other AWS Services
- All aws ec2 instances belong to some subnet in VPC.
- By default they get created in Default VPC
- Security Group: just think of it as a firewall
- What is type of hard disk which you want to use
- Instance Store
Other Things in EC2 to be considered
- AMI (Amazon Machine Image):
- Which OS has to be used to create EC2 instance
- Three kinds of AMIs
- AWS Managed:
- Managed by AWS with basic OS images and some extra softwares
- Market Place:
- Images created by Third Parties.
- Extra licensing costs can be imposed
- Custom Images:
- Images created by users.
- Generally will have your applications preconfigured.
- AWS Managed:
- AWS by default disables password authentication.
- Keypair RSA based Private and Public keys
- Can be created in AWS or Create them in your servers and import the public key to AWS.
- Instance Type:
- number of Cpus
- Size of RAM
- Network Speed
- Kind of Hardware
- Number of Instance Stores
Diagnostic Information about EC2 machines
- System Log:
- Instance Settings => Get System Log
- Instane Screen Shot:
- Instance Settings => Get Instance ScreenShot
- How to Change Instance Type of the EC2 Instance:
- Shutdown the EC2 instance
- Instance Settings => Change Instance Type
- Note: requires downtime.
- terminated => Deleted
- Roles can be attached and changed when ec2 machine is running.
Execute Some Script Once the EC2 machine is created