sharedstorage

Shared storage is a set of storage resources that can be accessed concurrently by multiple compute nodes and clients. It enables coordinated data access, centralized management, and easier data sharing across systems. Shared storage is often used in virtualization, clustering, and collaborative environments where data must be available to several servers at once.

Common implementations include storage area networks (SANs) and network-attached storage (NAS). SANs typically provide block-level access via Fibre Channel or iSCSI, while NAS provides file-level access via protocols such as NFS or SMB. In addition, distributed or software-defined storage systems such as Ceph, GlusterFS, or Lustre create a shared view of storage across commodity hardware, sometimes offering POSIX-compliant file systems or object interfaces.

Key use cases include hosting virtual machine disks for virtualized environments, enabling high-availability clusters and live migration, shared databases and files, and multi-node data analysis. Shared storage simplifies data protection through centralized backups, snapshots, and replication across sites.

Architecturally, shared storage relies on a centralized storage pool or a set of replicated storage nodes, with connectivity from multiple hosts. It requires concurrency control, data integrity mechanisms (such as locking and journaling), and appropriate network bandwidth. Redundancy, such as multipath I/O, RAID, or erasure coding, helps prevent data loss.

Challenges include cost, complexity, potential bottlenecks, and the risk of a single point of failure if not properly architected. Performance depends on network and storage subsystem design, including caching, tiering, and contention management. Access control, backups, and disaster recovery planning are essential.