Exploring AWS !!

Day 6:

Elastic Block Storage (EBS)

One physical volume divided into multiple logical volumes. It is the backbone for EC2. In an EBS block level storage, server-base OS connects with raw volumes which are created through fiber channels.
Then they are used as individual disks, and if its versatile it can be used as file storage, database storage and virtual machine volumes.
An EC2 volume is directly connected to EBS, while the instance is running, a volatile memory called ephemeral storage will be attached to instance. If instance is stopped, the ephemeral memory will be detached.

EBS Concepts:

It is a raw unformatted block level storage, it is exposed as raw device to EC2 instance.
EBS volumes persist independently from life of EC2 instance.
An EBS volume is automatically replicated within AZ.
Throughput — It is sequential transfer rate that an SSD or HDD will maintain continuously.
IOPS — measure of number of I/O operations a drive, SSD or HDD can handle per second with each block being read from or written to RANDOM location to disk.

Volume Types:

GP2 (General Purpose SSD) — size 1 GB — 16 TB
— Baseline performance is 3 IOPS/GB with minimum of 100 IOPS and a maximum of 10000 IOPS.
— Maximum burst performance is 3000 IOPS.
— Maximum throughput per volume 160 Mbps.

IO1: Provisioned SSD — size 4 GB — 16 TB
— From 100 to 32000 IOPS can be provisioned.
— Maximum throughput 500 Mbps.

ST1 Throughput Optimized HDD — size 500 GB — 16 TB
— Baseline performance 40 Mbps per TB with maximum of 500 Mbps per volume.
— Burst performance is 250 Mbps per TB with maximum of 500 Mbps per volume.

SC1 Cold Storage HDD — size — 500 GB — 16 TB
— Baseline performance 1 2Mbps per TB with maximum of 192 Mbps per volume.
— Burst performance is 80 Mbps per TB with maximum of 250 Mbps per volume.