storage gateway

1. Storage gateway VS Volume gateway

1.1. https://user-images.githubusercontent.com/13093517/84080932-05cc5380-a9ab-11ea-8dd5-a80717b1b067.png

1.2. https://user-images.githubusercontent.com/13093517/84081406-e5e95f80-a9ab-11ea-82d2-8bd1a53876ba.png

2. 3 gateway

2.1. File gateway

2.1.1. NFS or SMB

2.2. Tape gateway

2.3. volume gateway

2.3.1. store HD in s3

2.3.2. store main data in AWS and on prem acts as cache-no need to expand on premise

3. bridge between on-prem & aws