Discovering AWS: Storage

Simple Storage Service (S3)

It is not a file system, it is an object store. It has an unlimited store capacity, it is highly scalable and available, and exists inside a region, this means that object are not moved outside of the region unless you specify it. By default, all objects are replicated. All object exists in three different locations. It is a WORM store (Write Once, Read More) so it is perfect backups, log files, etc. even for static web pages for a web application.

Interfaces with S3 could be REST or SOAP, if we provide a key, data will be encrypted (AES-256) automatically. The name of our bucket could have 1024 characters as maximum, and it have to be unique (for all AWS, not just in our region or AZ).

It enables multipart upload (100 MB/piece, 10000 pieces as maximum), access control (using Amazon S3 policies, ACLs o IAM rules) and object versioning (you have to pay for both, original object and old version).

Reduced Redundancy Storage (RRS) is a new option inside S3 offering. It provides 99.99% of durability and availability, and a low level of redundancy. You pay 2/3 of S3 price.

Elastic Block Store (EBS)

EBS is for AWS the same that a SAN volume for a VMWare host. It is a simple storage volume that we could join to our EC2 instance. It is POSIX-Compliant (so you can use it as boot device). It is replicated automatically by default inside the same Availability Zone, and snapshots are stored in S3. A new EBS can be created from the snapshot and attach it to another EC2.

EBS volume is “portable”, you can move it from an instance to another (detach/attach), but it can’t be shared between different EC2 instances.

If we choice ESB-optimized option during the provisioning, the volume will be provisioned in a storage dedicated network zone that has a dedicated bandwidth.

You can use EBS Provisioned IOPS too. Differences between both solutions:

EBS Standard	EBS PIOPS
IOPS: 100 IOPS steady-state, with best-effort bursts to hundreds	IOPS: Within 10% of up to 4000 IOPS, 99.9% of given year, as provisioned
Throughput: variable by workload, best effort to 10s of MB/s	Throughput: 16 KB per I/O = up to 64 MB/s, as provisioned
Latency: Varies, reads typically < 20ms writes typically < 10ms	Latency: low and consistent. Second/IOPS, at recommended QD
Capacity: As provisioned, up to 1 TB	Capacity: As provisioned, up to 1 TB

In EBS Standard you pay for you use, in EBS PIOPS you pay for provisioned.

Glacier

Similar to S3 but used for archiving purposes. Its cost the tenth than S3 service, 1 cent/GB/month. It takes 3-5 hours to recover the data, so you should use it for data that you don’t need in your day-by-day. It is a WORN store (Write Once, Read Never), you pay for access to the data.

AWS Import/Export

AWS Import/Export accelerates moving large amounts of data into and out of AWS using portable storage devices for transport. AWS transfers your data directly onto and off of storage devices using Amazon’s high-speed internal network and bypassing the Internet. For significant data sets, AWS Import/Export is often faster than Internet transfer and more cost effective than upgrading your connectivity.