One Use Case where you CANT use S3 and have to use EFS or EBS

a lesser used service shines over S3? (Limited Time Special Offer Inside)

Hello frens, avatars, and other people who like learning about AWS cloud engineering. Today we are talking about one specific use case where EFS HAS to be used over S3. This comes up commonly during lift-and-shifts.

EFS vs EBS vs S3

S3 is probably a service that needs a deep dive, as it is a foundational service for AWS. S3 is great for a lot of things, but one thing it *cannot* handle is Symbolic Links (symlinks for short).

In computing, a symbolic link (also symlink or soft link) is a file whose purpose is to point to a file or directory (called the "target") by specifying a path thereto.

Symlinks are common in older or legacy applications. There is no way to handle this use case or requirement inside of S3. This type of functionality or behavior is not supported in S3. If you have a requirement for a symlink you must use EBS or EFS.

There are not that many differences between EFS and EBS, comes down to if you need the drive on >1 instance, then use EFS.

Some people make a fuss about not being able to mirror file permissions and such in S3. It is possible and not terribly complicated, just requires some IAM engineering.

S3 Structure

Remember that S3 is flat object storage. Even though in the Console/UI S3 is visually displayed as a file tree, it is not. This is a classic noob trap, if someone doesnt know this is fairly evident they have not spent much time working with S3.

Turbo Note: Virgin AWS Engineer interview question: What structure or hierarchy does S3 have? if the answer is anything besides flat, no way jose.

EFS and EBS structure

These guys follow the classic filesystem tree with all of the good stuff.

Conclusion

That is all folks. came up today and thought it was interesting. Had not encountered migrating a legacy application with symbolic links to AWS. Short and to the point. Let me know if you still enjoy shorter and to the point content.

Working on Lambda Deep Dive pt 4. Soon :)

Click button below for a good time :)