Amazon Cloud : AWS Linux Server Tips, Tricks & Tutorials

Amazon EC2 Reserved Instances (RI) provide a significant discount (up to 75%) compared to On-Demand pricing and provide a capacity reservation when used in a specific Availability Zone.   Why Should I Use RIs? Save Money and Maintain Flexibility RIs provide you with a significant discount (up to 75%) compared to On-Demand instance pricing. You have the flexibility to change families, OS types, and tenancies while benefitting from RI pricing when you use Convertible RIs. Reserve Capacity RIs can provide a capacity reservation, offering additional confidence in your ability to launch the number of instances you have reserved when you need them. How do RIs Work? EC2 RIs provide a discounted hourly rate and an optional capacity reservation for EC2 instances. AWS Billing automatically applies your RI’s discounted rate when attributes of EC2 instance usage match attributes of an active RI. If an Availability Zone is specified, EC2 reserves capaci...

In case when you lost private keys from AWS EC2 instances you will need a way to restore it. Unfortunately you can’t just change instance private key in AWS Management Console. The easiest way to do it which I found is through Amazon Machine Image (AMI). Basically all you need to do is recreate you instance from AMI and set new private key to it. Below I describe required steps to do it. Steps to change EC2 key pair 1. Shut down your instance   2. Create AMI for that instance and provide some meaningful name for them   3. Go to “Images > AMIs”. You need to launch instance with the same type from created AMI 4. On the last step of launching you will be asked about key pair. So it’s time to create/chose private key which you want to use with this instance 5. After that you need go to “Network & Security > Elastic IPs” and disassociate ip from old instance and associate with created instance...