# 12.1 Whizlabs - Free Test

1.  Amazon EBS encryption offers a simple encryption solution for your EBS volumes without the need to build, maintain, and secure your own key management infrastructure. When you create an encrypted EBS volume and attach it to a supported instance type, the following types of data are encrypted:\
    1\. Data at rest inside the volume\
    2\. All data moving between the volume and the instance\
    3\. All snapshots created from the volume\
    4\. All volumes created from those snapshots

    There is no direct way to encrypt an existing unencrypted volume, or to remove encryption from an encrypted volume. One can encrypt a volume from a snapshot by following the below steps:\
    1\. Create a snapshot of your unencrypted EBS volume. This snapshot is also unencrypted.\
    2\. Copy the snapshot while applying encryption parameters. The resulting target snapshot is encrypted.\
    3\. Restore the encrypted snapshot to a new volume, which is also encrypted.
2. The limit of your on-demand EC2 instances is 20. This limit is account level, so the number of your instances of all of Regions cannot exceed 20. This is a common reason that your auto-scaling group cannot scale out further.
3. DynamoDB uses Provisioned throughput capacity to control the read and write capacity on a table.
4. The 3 types of Alarm states of AWS CloudWatch:
   1. Alarm - the metric is outside of the defined threshold
   2. Insufficient - the alarm has just started, the metric is not available, or not enough data is available for the metric to determine the alarm state
   3. OK - the metric is within the defined threshold
5. Amazon Auto-scaling is not meant to handle instant load spikes but is built to grow with a gradual increase in usage over a short time period.
