Ceph

More About Ceph

Ceph is designed as a distributed, software-defined storage platform (storage infrastructure) that aggregates the local resources of many commodity servers into a unified cluster that presents object, block, and file storage services. It targets environments that require scale-out capacity, fault tolerance, and programmatic control over storage, such as cloud infrastructures, virtualized data centers, and large-scale data platforms.

At the core of Ceph is the Reliable Autonomic Distributed Object Store, or RADOS (distributed object store), which manages how data objects are stored, replicated, and retrieved across the cluster. RADOS uses an algorithmic data placement strategy to determine where objects reside, so clients interact with storage nodes directly without central metadata bottlenecks. This approach supports features such as replication, erasure coding, and automatic rebalancing when nodes are added, removed, or fail (data durability and availability).

Ceph exposes multiple storage interfaces built on RADOS. The RADOS Gateway, or RGW (object storage), provides an HTTP-based object storage service compatible with common cloud object APIs. The RADOS Block Device, or RBD (block storage), delivers network-attached block devices suitable for Virtual Machine (VM) disks and application volumes, with features such as thin provisioning and snapshots where configured. CephFS (distributed file storage) offers a POSIX-compliant shared file system that stores its metadata and file data on RADOS, enabling scalable file-based access with support for multiple active clients.

In enterprise environments, Ceph clusters are typically deployed on racks of x86 or similar servers with local disks or SSDs, interconnected through IP networks. A Ceph deployment includes monitor daemons (cluster coordination), object storage daemons, or OSDs (data storage), and optional metadata servers, or MDS, for CephFS (file system metadata management). Management and operations are supported through the Ceph Manager daemons, which host management modules, dashboards, and integration points with external tooling (operations and observability).

Ceph integrates with virtualization and container platforms through drivers and plugins (cloud and virtualization integration), allowing it to back VM volumes, Kubernetes persistent volumes, and cloud-native workloads using the same underlying cluster. It supports security controls such as access keys and capabilities for object storage and client authentication through its internal mechanisms (storage security). In an enterprise directory or taxonomy, Ceph is classified as software-defined storage, covering distributed object storage, block storage, and distributed file systems, and is used as a foundational data services layer for private cloud, on-premises (on-prem) infrastructure, and hybrid environments.