Storage is another generic service that is expected from all cloud vendors. AWS provides services for block storage, file storage, and object storage. Additionally, AWS also provides Storage Gateway solutions, which are hybrid cloud solutions. We will look at each one in detail in the following list:

• Simple Storage Service (S3): Simple Storage Service, or S3, as it is popularly known, was one of the first services introduced by Amazon for the general public. S3 is an object-based storage service. You can store an unlimited number of objects in S3. It has multiple classes of storage, each of which has a different cost. The standard class has the highest SLA of 11 nines of durability and is designed for four nines of availability. Objects in S3 are accessed using REST APIs. S3 is a natural destination for cloud backup solutions. 
• Glacier: Glacier is an archival storage solution from Amazon. It is a very low-cost solution, with the cost per GB being less than a cent for long-term storage. Objects in Glacier have a durability of 11 nines. AWS offers different levels of retrieval: expedited, standard, and bulk. Expedited retrieval retrieves objects within 1-5 minutes, and the standard is between 5 and 12 hours, with the bulk taking more than 12 hours to retrieve an object. Each retrieval type has a different cost.
• Elastic Block Store (EBS): EBS is a block storage solution from AWS. EBS disks, also called volumes, are disks that are attached to EC2 instances. EBS volumes come in different varieties: throughput optimized, magnetic, general-purpose SSD, and provisioned IOPS. The maximum EBS volume size is 16 TB. EBS volumes support snapshots for backing up. All snapshot backups are stored in S3. Volumes can be attached and detached at any point in time. 
• Instance Store: This is another block storage service from AWS. It is temporary block-level storage for the instance, where the storage is provided by the disks that are physically attached to the bare metal on which the VM resides.
• Elastic File System (EFS): EFS is a file storage service from AWS. EFS is based on NFS v4.1, and instances that run Linux can concurrently mount EFS. EFS has no space limits and can store an infinite number of files. Computers in data centers can mount EFS over Direct Connect.
• Storage Gateways: Storage Gateways is a hybrid cloud solution, enabling on-premises equipment to connect to AWS storage. Storage Gateway can be installed as a Virtual Appliance (VA) on-premises, or it can be deployed on an AWS EC2 instance. There are three types of Storage Gateways: a volume gateway, a file gateway, and a tape gateway. These are outlined in the following list:
  • Volume gateway: A volume gateway provides cloud storage as iSCSI volumes that can be mounted by application servers in the data center. Volume gateways come in two types: cached volume gateways and stored volume gateways. In a cached volume gateway, the data is stored in Amazon S3. The local disk stores a cache of the data for faster access. In a storage volume gateway, data is stored locally, and at regular intervals a snapshot of the data is taken and stored in S3.
  • File gateway: A file gateway allows you to access files from S3 using NFS v4.1. In other words, the file gateway provides a file interface to S3, allowing the application servers in the data center to store and retrieve objects to and from S3, using a file interface. 
  • Tape gateway: A tape gateway provides a Virtual Tape Library (VTL) interface and allows the files to be stored in Glacier for archival purposes.