Problem scenario
The needs for a server have changed. You now want your AWS EC-2 virtual server to have more CPU and RAM, but you do not want to migrate to a new instance. You can only afford 15 minutes of down time. What should you do to resize the server's capacity to have more processors and greater memory?
Solution
These basic steps will work if you want to downgrade your server too (to save money).
1. This is an optional step if the instance is running Linux (as a "sanity check"). From the instance, check the amount of RAM and number of processors with these commands:free -mh
cat /proc/cpuinfo | grep processor | tail -n 1
2. The following steps are performed from the AWS console (except the last step which is optional). In the AWS console go to the EC2 instance screen.
3. Check the radio button on the left column for the instance (the row that has information about the instance you want to modify).
4. Go to Actions -> Instance State -> Stop.
5. When it has stopped go to Actions -> Instance Settings -> Change Instance Type.
6. In the pop-up choose the Instance Type you want (e.g., m4.xlarge). Click "Apply."
7. Go to Actions -> Instance State -> Start.
8. To the next prompt, click "Yes, Start."
9. You are done. This is an optional step if the instance is running Linux. From the instance, check the amount of RAM and number of processors with these commands:free -mh
cat /proc/cpuinfo | grep processor | tail -n 1