AWS EFS vs EBS vs S3 (differences & when to use?)

Question

As per the title of this question, what are the practical differences between AWS EFS, EBS and S3?

My understanding of each:

• S3 is a storage facility a

Answer 1

I wonder why people are not highlighting the MOST compelling reason in favor of EFS. EFS can be mounted on more than one EC2 instance at the same time, enabling access to files on EFS at the same time.

(Edit 2020 May, EBS supports mounting to multiple EC2 at same time now as well, see: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-volumes-multi.html)

Answer 2

To add to the comparison: (burst)read/write-performance on EFS depends on gathered credits. Gathering of credits depends on the amount of data you store on it. More date -> more credits. That means that when you only need a few GB of storage which is read or written often you will run out of credits very soon and througphput drops to about 50kb/s. The only way to fix this (in my case) was to add large dummy files to increase the rate credits are earned. However more storage -> more cost.

Answer 3

Apart from price and features, the throughput also varies greatly (as mentioned by user1677120):

EBS

Taken from EBS docs:

| EBS volume | Throughput |           Throughput          |
|    type    |   MiB/s    |         dependent on..        |
|------------|------------|-------------------------------|
| gp2 (SSD)  | 128-160    | volume size                   |
| io1 (SSD)  | 0.25-500   | IOPS (256Kib/s per IOPS)      |
| st1 (HDD)  | 20-500     | volume size (40Mib/s per TiB) |
| sc1 (HDD)  | 6-250      | volume size (12Mib/s per TiB) |

Note, that for io1, st1 and sc1 you can burst throughput traffic to at least 125Mib/s, but to 500Mib/s, depending on volume size.

You can further increase throughput by e.g. deploying EBS volumes as RAID0

EFS

Taken from EFS docs

| Filesystem |    Base    |   Burst    |
|    Size    | Throughput | Throughput |
|    GiB     |   MiB/s    |   MiB/s    |
|------------|------------|------------|
|         10 |        0.5 |        100 |
|        256 |       12.5 |        100 |
|        512 |       25.0 |        100 |
|       1024 |       50.0 |        100 |
|       1536 |       75.0 |        150 |
|       2048 |      100.0 |        200 |
|       3072 |      150.0 |        300 |
|       4096 |      200.0 |        400 |

The base throughput is guaranteed, burst throughput uses up credits you gathered while being below the base throughput (so you'll only have this for a limited time, see here for more details.

S3

S3 is a total different thing, so it cannot really be compared to EBS and EFS. Plus: There are no published throughput metrics for S3. You can improve throughput by downloading in parallel (I somewhere read AWS states you would have basically unlimited throughput this way), or adding CloudFront to the mix

Answer 4

EFS & S3 have the same purpose, you can store any kind of object or files.

But for me the only difference is EFS is allowing you to have a traditional file system in the VM(EC2) cloud with more flexibility like you can attach to multiple instances.

S3, on the other hand, is a separate flexible and elastic server for your objects. It can be used for your static files, images, videos or even hosting static app (js).

EBS is obviously for block storage where you can install OS or anything related to your OS.