AWS Storage

AWS offers a comprehensive suite of storage services across three categories: object storage (S3, Glacier), block storage (EBS), and file storage (EFS, FSx). Each serves different access patterns and performance requirements.

Service Map

Service	Type	Access Pattern	Common Use
S3	Object	HTTP REST API (PUT/GET/DELETE)	Static assets, data lake, backup
EBS	Block	EC2 attachment (iSCSI)	OS disks, databases, app data
EFS	File	NFSv4 (mounted as drive)	Shared file system, CI runners
FSx	File	SMB/NFS (Windows/Lustre)	Enterprise apps, HPC
Glacier	Object	HTTP (via S3 or direct)	Long-term archive, compliance
Storage Gateway	Hybrid	SMB/NFS/iSCSI	On-prem to cloud backup

Storage Hierarchy

Object Storage (S3, Glacier)
  └── Bucket
       ├── Object (key-value, no hierarchy)
       ├── Prefix (logical folder: "logs/2024/")
       └── Lifecycle rules

File Storage (EFS, FSx)
  └── File System
       ├── Directory
       └── File

Block Storage (EBS)
  └── Volume
       └── Partition
            └── File System (ext4, xfs, ntfs)

Storage Decision Tree

Is it attached to a single EC2 instance?
  YES → EBS (block, high-performance, single attachment)
  NO ↓

Is it shared across multiple instances?
  YES → Is it Windows-based?
      YES → FSx for Windows (SMB, AD integration)
      NO → Is it high-performance computing (HPC)?
          YES → FSx for Lustre (parallel, petabyte scale)
          NO → EFS (NFS, scalable, multi-AZ)
  NO ↓

Is it accessed over HTTP?
  YES → S3 (REST API, global, infinitely scalable)
  NO ↓

Is it long-term archive (months to years)?
  YES → S3 Glacier (or S3 Glacier Instant Retrieval)
  NO ↓

Is it a hybrid cloud backup from on-premises?
  YES → Storage Gateway (File/Snapshot/Tape)
  NO → Re-evaluate access pattern

Architecture Patterns

Tiered Storage (Hot → Warm → Cold)

S3 Standard         → Frequently accessed (CDN origin, app assets)
         ↓ lifecycle (30 days)
S3 IA               → Less frequently accessed (backups, analytics)
         ↓ lifecycle (90 days)
S3 Glacier          → Rarely accessed (compliance, legal hold)

Hybrid Cloud Storage

On-Premises Data Center
  └── Storage Gateway (VM)
        ├── File Mode → S3 (NFS/SMB)
        ├── Tape Mode → S3 → Glacier (virtual tape library)
        └── Volume Mode → EBS Snapshots → S3
              ↓
        AWS Cloud (S3/Glacier)

AWS Services Organized by Category

Object Storage

• S3 — The primary object storage service
• Glacier — Long-term archival storage

Block Storage

• EBS — EC2 instance block storage

File Storage

• EFS — NFS file system for Linux workloads
• FSx — Managed Windows (SMB) and Lustre file systems

Hybrid Storage

• Storage Gateway — Connect on-premises to cloud storage

References

• Homepage: https://aws.amazon.com/products/storage/
• Documentation: https://docs.aws.amazon.com/storage/
• Pricing: https://aws.amazon.com/pricing/storage/

Nuggets & Gotchas

• S3 is object storage, not a file system — you can’t mount it as a drive: Applications expecting POSIX semantics (directory rename, file locking) may not work with S3. Use EFS or FSx for those use cases.
• EBS volumes are AZ-specific — they cannot span multiple AZs: If you need cross-AZ storage, use EFS (NFS) or S3. EBS is a single-AZ resource with 99.999% uptime SLA (not multi-AZ like RDS).
• EFS and FSx are network file systems — latency is higher than EBS: EFS uses NFS over the network, so expect 0.5–2ms additional latency vs local EBS. For latency-sensitive databases, use EBS.
• S3 storage class selection is a trade-off between cost and retrieval time: S3 Standard retrieval: milliseconds. S3 IA retrieval: 1-5ms. S3 Glacier retrieval: 1-12 hours (or 1-5 minutes with expedited). Choose based on access frequency.
• Storage Gateway has ongoing bandwidth costs for data transfer: While the gateway VM is free, data transfer from on-premises to S3 via Storage Gateway costs $0.02–$0.09/GB depending on region. Model bandwidth costs before committing.