AWS Classroom Series – 28/Aug/2020

How EBS Snapshots work in AWS

• EBS snapshot is a point-in-time copy of your EBS volume, which is lazily copied into AWS S3.

• EBS Snapshots are incremental copies of data.

• Lets assume we have a EBS Volume & we have taken the snapshot of it

• Now there were some changes done to EBS volume and if the snapshot is taken

• Now there were some changes done to EBS volume and if the snapshot is taken

• Now if we create volume from snapshot3 the volume with the data of snapshot3, snapshot2 and snapshot1 will be created

• Now if we create volume from snapshot2 the volume with the data of snapshot2 and snapshot1 will be created

• What will happen if i delete snapshot3. If i delete the latest snapshot the data changes that were done in the latest snapshot will be lost

• What will happen if i delete snapshot2.

• In AWS we loose data only if we delete latest snapshots not older ones.

• AWS AMI (Amazon Machine Image) is a snapshot of disk(s) plus some additional metadata.

• Non Backup Scenarios:

  1. I have an ebs volume in mumbai region in az (ap-south-1b) and i want to create another ebs volume with same data in different az (ap-south-1a)
     • Create a snapshot of the ebs volume from az (ap-south-1b)
     • From the snapshot create a ebs volume in ap-south-1a az
  2. I have an ebs volume in mumbai region in az (ap-south-1b) and i want to create another ebs with same data in different region oregon (us-west-2)
     • Create a snapshot of ebs volume from az (ap-south-1b)
     • Now copy the snapshot to oregon (us-west-2)
     • From the copied snapshot create an ebs volume
  3. I have an ebs volume in mumbai region in az (ap-south-1b) and my friend wants to create the same ebs volume in his aws account.
     • Create a snapshot of ebs volume from az (ap-south-1b) and modify permissions to add your friends aws account id to your snapshot

Pricing of EBS Snapshots

• EBS Snapshot will have a fixed price of approx $0.05 per GB-month

Automatic Snapshot creations

• It makes sense for us to automatically create snapshots. There are many ways of doing it
  • Using AWS CLI, develop a shell/batch script to take a snapshot & run it as scheduled or cron job
  • Using AWS SDK, develop a script/code to take automatic snapshots
  • Configure Lifecycle manager

Next Class Prep

• Ensure you have aws cli configured as shown Here