These three get mixed up more than any other trio on the architect exam, so here’s the short version you can actually remember.
The plain-English difference
EBS is a hard drive for one server — the disk an EC2 instance boots from. EFS is a shared drive many Linux servers mount at once. S3 is internet-facing object storage you reach by API. And if it says Windows shared files, that’s FSx, not EFS.
Test yourself
A fleet of Linux web servers must read and write to the SAME file system simultaneously. Which storage service fits best?
- Amazon EBS
- Amazon EFS
- Amazon S3
- EC2 instance store
👉 Click to reveal the answer & explanation
Correct answer: B. EFS is a shared, elastic file system multiple Linux instances mount concurrently. EBS (A) attaches to a single instance; S3 (C) is object storage you can’t mount like a folder; instance store (D) is temporary.
Related topics
Amazon S3 · Amazon RDS · Amazon EC2
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