what is the best shared storage for app servers

The “best” shared storage for app servers depends on what you mean by shared and what the servers need to do with it. In practice, the best choice is usually one of these:

1. Network file storage (NAS)

Best for: shared files, web content, user uploads, home directories, app assets

• Examples: NFS, SMB/CIFS, managed services like AWS EFS, Azure Files, Google Filestore
• Pros:
  • Easy to mount on multiple app servers
  • Simple to use with legacy apps expecting a filesystem
  • Good for shared read/write files
• Cons:
  • Can become a bottleneck for very high IOPS workloads
  • File locking and latency can be issues for some apps

2. Distributed block storage / clustered storage

Best for: workloads needing higher performance, scalability, or stronger availability

• Examples: Ceph, GlusterFS (less common now), vSAN, EBS with clustering, managed SAN-like offerings
• Pros:
  • Better performance and resilience than basic NAS in some setups
  • Can scale across nodes
• Cons:
  • More complex to deploy and operate
  • May be overkill for simple app-server sharing

3. Object storage

Best for: static files, backups, logs, media, application artifacts

• Examples: S3, Azure Blob, Google Cloud Storage
• Pros:
  • Highly scalable and durable
  • Cheap relative to block/file storage
  • Great for decoupling app servers from shared state
• Cons:
  • Not a normal mounted filesystem
  • Apps need to be adapted to use object APIs

Most common answer

If your app servers need a shared mounted filesystem, the best general-purpose option is usually:

• Managed NFS/NAS (like AWS EFS or an equivalent cloud file service)

If your app can be redesigned to avoid shared filesystem dependency, object storage is often better long-term.

Quick recommendation by use case

• Multiple app servers need same files via mount: NFS / managed file storage
• Static assets, uploads, backups: object storage
• Very high performance / enterprise storage needs: clustered/distributed storage or SAN/NAS appliance

If you tell me:

1. on-prem or cloud,
2. read-heavy or write-heavy,
3. how many servers,
4. filesystem vs object storage, I can recommend a specific option.