Virtual hard disk. Block based storage.

Generalities

  • Tied to a single AZ
  • Can be attached to only one EC2 instance at once
  • EBS has to be in the AZ (subnet) than the EC2.
    • Otherwise move the EBS to other AZ by creating a Snapshot. Same for regions.
  • Can be modified/upgraded on the fly
  • Multiple EBS mounted in a EC2 can help to form a RAID 5/10/0

Defaults

  • Termination protection is turned off by default
  • EBS root vol is by default deleted once upon EC2 termination

Encryption

  • EBS root volume CAN NOW be encrypted (only via thrid party solutions). non-root volumes can be encrypted.

Types

  • General purpose SSD (GP2): SSD
    • ratio of 3iops per GB up to 10000iops
    • ability to burst up to 3000iops for extended periods of time on 3334Gb volumes and above
  • Provisioned IOPS SSD (IO1): SSD
    • high performance apps
    • NOSql databases
    • more than 10000iops
    • low latency
  • Throughput optimized HDD (ST1): Magnetic
    • low cost for frequently access
    • big data, data warehouses
    • cannot be a boot volume
    • log processing
  • Cold HDD (SC1): Magnetic
    • low cost for less frequently access
    • low cost
  • Magnetic: Magnetic
    • lowest cost per Gb
    • legacy option!
    • data access infrequently
    • can be a boot volume

Snapshots

  • Stored in S3
  • Snapshots are incremental copies
  • AMIs can be created from a EBS
  • Shareable snapshots cannot be encrypted
  • Snapshots can be migrated to new AZ or Region
  • Snapshots are cost effective
  • Service AWS Data Lifecycle Manager to automate snapshots + retention rules

Charges / Pricing

  • SDD ebs are more expensive than HDD ebs