EBS vs EFS¶

• EBS volumes

  • can be attached to only one instance at a time
  • are locked at the Availability Zone (AZ) level
  • gp2: IO increases if the disk size increases
  • io1: can increase IO independently
  • To migrate an EBS volume accross AZ
    • take a snapshot
    • Restore the snapshot to another AZ
    • EBS backups use IO and you shouldn't run them while your application is handling a lot of traffic
  • Root EBS volumes of instances get terminated by default if the EC2 instance gets terminated. (you can disable that).

• EFS volumes

  • Mounting 100s of instances accross AZ
  • EFS share website files (wordpress)
  • Only for linux instances (POSIX)
  • EFS has a higher price point than EBS
  • Can leverage EFS-IA for cost savings

Rembmer: EFS vs EBS vs Instance Store