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Silver1050

System Design

The Object Storage Model

Why blobs live in a flat keyed store instead of a tree of folders and inodes.

4 min read · intro · beat Silver to climb

What it is

Object storage treats each file as a self contained object: the raw bytes plus a bundle of metadata, addressed by a single unique key. Unlike a filesystem there are no nested directories, no inodes, and no in place editing. You put a whole object or get a whole object.

Why it scales

  • The namespace is flat, so the system never walks a deep directory tree to find a file.
  • Objects are immutable in practice: you replace the whole thing rather than seeking into the middle. That makes replication and caching simple.
  • Metadata travels with the object, so a request needs no separate stat call.

What you give up

  • No partial writes or appends in the middle of a blob.
  • No real folders, only a key that may look like a path.
  • Strong filesystem semantics like locking are replaced by simpler put and get.

Key idea

Object storage swaps a mutable directory tree for a flat keyed store of immutable blobs, trading rich filesystem semantics for massive scale.

Check yourself

Answer to earn rating on the learn ladder.

1. How does an object store address a file?

2. What operation is NOT native to object storage?