Amazon Elastic Compute Cloud
User Guide for Linux Instances

Amazon Elastic Block Store (Amazon EBS)

Amazon Elastic Block Store (Amazon EBS) provides block level storage volumes for use with EC2 instances. EBS volumes are highly available and reliable storage volumes that can be attached to any running instance that is in the same Availability Zone. EBS volumes that are attached to an EC2 instance are exposed as storage volumes that persist independently from the life of the instance. With Amazon EBS, you pay only for what you use. For more information about Amazon EBS pricing, see the Projecting Costs section of the Amazon Elastic Block Store page.

Amazon EBS is recommended when data must be quickly accessible and requires long-term persistence. EBS volumes are particularly well-suited for use as the primary storage for file systems, databases, or for any applications that require fine granular updates and access to raw, unformatted, block-level storage. Amazon EBS is well suited to both database-style applications that rely on random reads and writes, and to throughput-intensive applications that perform long, continuous reads and writes.

For simplified data encryption, you can launch your EBS volumes as encrypted volumes. Amazon EBS encryption offers you a simple encryption solution for your EBS volumes without the need for you to build, manage, and secure your own key management infrastructure. When you create an encrypted EBS volume and attach it to a supported instance type, data stored at rest on the volume, disk I/O, and snapshots created from the volume are all encrypted. The encryption occurs on the servers that host EC2 instances, providing encryption of data-in-transit from EC2 instances to EBS storage. For more information, see Amazon EBS Encryption.

Amazon EBS encryption uses AWS Key Management Service (AWS KMS) master keys when creating encrypted volumes and any snapshots created from your encrypted volumes. The first time you create an encrypted EBS volume in a Region, a default master key is created for you automatically. This key is used for Amazon EBS encryption unless you select a Customer Master Key (CMK) that you created separately using the AWS Key Management Service. Creating your own CMK gives you greater flexibility when defining access controls, including the ability to create, rotate, disable, and audit encryption keys that are specific to individual applications and users. For more information, see the AWS Key Management Service Developer Guide.

You can attach multiple volumes to the same instance within the limits specified by your AWS account. Your account has a limit on the number of EBS volumes that you can use, and the total storage available to you. For more information about these limits, and how to request an increase in your limits, see Request to Increase the Amazon EBS Volume Limit.

Features of Amazon EBS

  • You can create EBS General Purpose SSD (gp2), Provisioned IOPS SSD (io1), Throughput Optimized HDD (st1), and Cold HDD (sc1) volumes up to 16 TiB in size. You can mount these volumes as devices on your Amazon EC2 instances. You can mount multiple volumes on the same instance, but each volume can be attached to only one instance at a time. You can dynamically change the configuration of a volume attached to an instance. For more information, see Creating an Amazon EBS Volume.

  • With General Purpose SSD (gp2) volumes, you can expect base performance of 3 IOPS/GiB, with the ability to burst to 3,000 IOPS for extended periods of time. Gp2 volumes are ideal for a broad range of use cases such as boot volumes, small and medium-size databases, and development and test environments. Gp2 volumes support up to 16,000 IOPS and 250 MiB/s of throughput. For more information, see General Purpose SSD (gp2) Volumes.

  • With Provisioned IOPS SSD (io1) volumes, you can provision a specific level of I/O performance. Io1 volumes support up to 64,000 IOPS and 1,000 MB/s of throughput. This allows you to predictably scale to tens of thousands of IOPS per EC2 instance. For more information, see Provisioned IOPS SSD (io1) Volumes.

  • Throughput Optimized HDD (st1) volumes provide low-cost magnetic storage that defines performance in terms of throughput rather than IOPS. With throughput of up to 500 MiB/s, this volume type is a good fit for large, sequential workloads such as Amazon EMR, ETL, data warehouses, and log processing. For more information, see Throughput Optimized HDD (st1) Volumes.

  • Cold HDD (sc1) volumes provide low-cost magnetic storage that defines performance in terms of throughput rather than IOPS. With throughput of up to 250 MiB/s, sc1 is a good fit ideal for large, sequential, cold-data workloads. If you require infrequent access to your data and are looking to save costs, sc1 provides inexpensive block storage. For more information, see Cold HDD (sc1) Volumes.

  • EBS volumes behave like raw, unformatted block devices. You can create a file system on top of these volumes, or use them in any other way you would use a block device (like a hard drive). For more information on creating file systems and mounting volumes, see Making an Amazon EBS Volume Available for Use on Linux.

  • You can use encrypted EBS volumes to meet a wide range of data-at-rest encryption requirements for regulated/audited data and applications. For more information, see Amazon EBS Encryption.

  • You can create point-in-time snapshots of EBS volumes, which are persisted to Amazon S3. Snapshots protect data for long-term durability, and they can be used as the starting point for new EBS volumes. The same snapshot can be used to instantiate as many volumes as you wish. These snapshots can be copied across AWS Regions. For more information, see Amazon EBS Snapshots.

  • EBS volumes are created in a specific Availability Zone, and can then be attached to any instances in that same Availability Zone. To make a volume available outside of the Availability Zone, you can create a snapshot and restore that snapshot to a new volume anywhere in that Region. You can copy snapshots to other Regions and then restore them to new volumes there, making it easier to leverage multiple AWS Regions for geographical expansion, data center migration, and disaster recovery. For more information, see Creating Amazon EBS Snapshots, Restoring an Amazon EBS Volume from a Snapshot, and Copying an Amazon EBS Snapshot.

  • Performance metrics, such as bandwidth, throughput, latency, and average queue length, are available through the AWS Management Console. These metrics, provided by Amazon CloudWatch, allow you to monitor the performance of your volumes to make sure that you are providing enough performance for your applications without paying for resources you don't need. For more information, see Amazon EBS Volume Performance on Linux Instances.

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