🧱 Architectural Comparison: File Systems (ext4 + POSIX) vs. Object Storage (TOS + S3 API)

In the evolution of storage architecture, different storage methods correspond to distinct system implementations and protocol access layers. The following diagram illustrates their hierarchical relationships:

                 🧠 Application Layer (App/Service/Framework)
                          ↓
          File Access Interface (POSIX) | Object Access Interface (S3 API)
                          ↓
	  ┌─────────────────────┬───────────────────────┐
	  │ File System (ext4/xfs) │   Object Storage (TOS, etc.)  │
	  └─────────────────────┴───────────────────────┘
                          ↓
                  Storage Media (HDD/SSD/Distributed Disk)

✅ Core Insight: File storage and object storage are two distinct access models, but at the architectural level, they serve as parallel “data access methods.”

🔍 Comparative Analysis: File Storage vs. Object Storage

Dimension	File Storage	Object Storage
Access Method	POSIX API (e.g., open/read/write)	HTTP API (e.g., PUT/GET), S3 API
Integration	Used via “mounting” directories	Upload/download via API calls
Path Identification	File path (e.g., `/mnt/data/xxx.txt`)	Bucket/Key (e.g., `my-bucket/folder/xxx.txt`)
Metadata	System-defined (filename, size, permissions, etc.)	Customizable metadata, tags, etc.
Use Case	Local storage, low-latency read/write	Massive data storage, backups, large files, multimedia
Scalability	Limited by single-machine disk capacity	Cloud-native architecture, near-infinite scalability
Consistency	Strong consistency	Usually eventual consistency (Note: TOS supports strong consistency)

💡 Core Summary

File storage is better suited for local structured file access, while object storage (such as TOS) provides a cloud-native storage solution based on HTTP interfaces, designed for massive data scale.

Analogy:

ext4/xfs: Like “carving” directly onto a disk, emphasizing strong locality and block structure.
TOS/S3: Like encapsulating files as objects and hosting them in the cloud via APIs, emphasizing distribution and high reliability.

🎯 Advanced: Can Object Storage Be Operated Like a File System?

The answer is yes. Through specific compatibility layers, object storage can be “file-systemized”:

Tool Support: TOS provides SDKs, CLI tools, and mounting utilities (e.g., s3fs).
Mounting Solutions: You can mount an object storage bucket to a local directory using mountpoint or similar tools. However, note that this essentially simulates file system behavior, and performance may differ from a native file system.

📌 Scenario Selection Guide

Scenario	Recommended: ext4/xfs	Recommended: S3 API / TOS
Frequent Log Writing	✅ (Low latency, ideal for local writes)	❌ (Not optimized for frequent small random writes)
User Video Upload/Download	❌ (Not suitable for massive large-file storage)	✅ (TOS is optimized for large object storage)
Big Data Platform Intermediate Data	✅ (e.g., HDFS/ext4/xfs)	✅ (Suitable for archiving cold data to TOS)
CDN Origin Source	❌	✅ (TOS as origin, best paired with caching)