Distributed storage systems spread data across multiple servers, providing scalability, fault tolerance, and high availability. This guide covers the fundamentals to help you choose and deploy the right solution for your infrastructure.
What is Distributed Storage?
Distributed storage is a method of storing data across multiple physical servers or nodes, rather than on a single machine. The data is typically replicated or erasure-coded to ensure durability and availability even when individual nodes fail.
Key Benefits
Scalability
Add capacity by adding more nodes
Fault Tolerance
Survive node failures without data loss
High Availability
Continuous access even during failures
Performance
Parallel I/O across multiple nodes
Types of Distributed Storage
Block Storage
Provides raw block devices that can be formatted with any filesystem. Ideal for databases and applications requiring low-latency access.
Examples: Ceph RBD, iSCSI, AWS EBS
File Storage
Presents a POSIX-compatible filesystem interface. Files and directories are accessible via standard filesystem operations.
Examples: GlusterFS, CephFS, NFS, MooseFS
Object Storage
Stores data as objects with metadata and unique identifiers. Accessed via HTTP/REST APIs. Best for unstructured data at scale.
Examples: MinIO, Ceph RADOS, S3
Common Architectures
Centralized Metadata
A dedicated metadata server tracks file locations and directory structures. Data is distributed across storage nodes while metadata operations go through the central server.
Distributed Metadata
Metadata is distributed across all nodes using consistent hashing or similar algorithms. No single point of failure, but more complex coordination.
Peer-to-Peer
All nodes are equal participants. Data discovery and routing happen through distributed algorithms. Highly resilient but may have higher latency.
Key Concepts
Replication
Data is copied to multiple nodes (replicas). A replication factor of 3 means three copies exist. Simple to understand but uses more storage.
# Example: 3-way replication
Data Block A → Node 1, Node 2, Node 3
Storage Used: 3x original sizeErasure Coding
Data is split into chunks and encoded with parity information. Can tolerate failures with less storage overhead than replication.
# Example: 4+2 erasure coding
Data → 4 data chunks + 2 parity chunks
Can lose any 2 chunks and recover
Storage Used: 1.5x original sizeConsistency Models
Strong Consistency
All nodes see the same data at the same time. Higher latency but simpler to reason about.
Eventual Consistency
Updates propagate over time. Lower latency and better availability, but temporary inconsistencies possible.
CAP Theorem
Distributed systems can only guarantee two of three properties: Consistency, Availability, and Partition tolerance. Understanding this trade-off is crucial for choosing the right storage system for your use case.
Use Cases
High-Performance Computing
Parallel file systems for compute clusters requiring high-throughput I/O.
Database Backends
Block storage for distributed databases like PostgreSQL, MySQL, or MongoDB clusters.
Backup & Archival
Object storage for cost-effective, durable long-term data retention.
Container Storage
Persistent volumes for Kubernetes and Docker Swarm workloads.
Popular Solutions
These distributed storage solutions can be deployed on RamNode Cloud VPS instances. See our deployment guides for step-by-step instructions.
GlusterFS
A scalable network filesystem suitable for cloud storage, media streaming, and data-intensive tasks. Supports replication, distribution, and erasure coding.
CephFS
Enterprise-grade unified storage providing block, file, and object storage from a single platform. Powers many OpenStack deployments.
MooseFS
Fault-tolerant distributed filesystem designed for petabyte-scale storage. Features snapshots, trash bin, and tiered storage.
JuiceFS
Cloud-native distributed filesystem that uses object storage as the data backend. Perfect for Kubernetes and hybrid cloud environments.
Syncthing
Peer-to-peer file synchronization for keeping directories in sync across multiple devices. No central server required.
Choosing the Right Solution
Decision Matrix
| Requirement | Recommended Solution |
|---|---|
| Simple file sharing across servers | GlusterFS, Syncthing |
| Block storage for databases | Ceph RBD, RamNode Block Storage |
| S3-compatible object storage | MinIO, Ceph RADOS Gateway |
| Kubernetes persistent volumes | CephFS, JuiceFS, GlusterFS |
| Petabyte-scale archival | MooseFS, CephFS |
| Hybrid cloud with object backend | JuiceFS |
Consider Your Scale
Distributed storage adds complexity. For small deployments (under 3 nodes), consider simpler solutions like NFS or rsync before adopting a full distributed filesystem.
Distributed Storage on RamNode
RamNode Cloud VPS provides an excellent foundation for building distributed storage clusters with private networking, block storage volumes, and high-performance NVMe storage.
Private Networks
Use private networks for storage traffic between nodes, keeping data off the public internet and reducing latency.
Learn about Private Networks →Block Storage Volumes
Attach additional NVMe block storage to nodes for dedicated storage capacity that can be moved between instances.
Learn about Block Storage →Recommended Cluster Sizing
Development/Testing: 3 nodes minimum (Standard Cloud VPS)
Production: 5+ nodes with dedicated block storage (Premium Cloud VPS)
High Performance: Dedicated CPU VPS with NVMe storage for latency-sensitive workloads
Best Practices
Use Dedicated Storage Networks
Separate storage traffic from application traffic using private networks to prevent bandwidth contention.
Plan for Failure
Design clusters to tolerate at least one node failure. Use odd numbers of nodes for consensus-based systems.
Monitor Cluster Health
Implement monitoring for disk usage, replication status, and node connectivity. Catch issues before they become outages.
Test Recovery Procedures
Regularly test node failure and recovery in a non-production environment. Know how long recovery takes.
Start Simple, Scale Later
Begin with a minimal cluster and add nodes as needed. Most distributed storage systems support online expansion.