Network storage systems refer to storage devices that are connected to a network and provide access to data storage for multiple users and devices on the network. They allow centralized data storage and management independent of the client devices. This enables easier data sharing and collaboration among users (What is Network Attached Storage (NAS)?).
The key purpose and benefits of network storage systems include:
- Centralized storage – Store data in a central location accessible to multiple users
- Improved data access – Enable users to access data from anywhere on the network
- Enhanced collaboration – Allow multiple users to collaborate by accessing the same data
- Data protection – Provide redundancy, backups, and disaster recovery capabilities
- Scalability – Additional storage can be added as needed
- Management efficiency – Storage resources can be managed centrally
By providing consolidated and shared data storage, network storage systems make data access, sharing and protection more efficient compared to separate local storage on individual devices.
History and Evolution
Network storage systems originated in the early 1980s with the development of file servers that enabled multiple users to access files and applications stored on centralized disks over a local area network (LAN) (Source). Key innovations included network-attached storage (NAS) in the 1990s, which provided dedicated file-based access over Ethernet networks, and storage area networks (SAN) in the late 1990s, which provided block-level access over Fibre Channel networks.
Over the years, network storage systems have evolved to keep pace with growing data storage and access needs. Key innovations include improvements in bandwidth, capacity, and performance; new interconnect technologies like Fibre Channel over Ethernet (FCoE) and iSCSI; data reduction and optimization techniques like deduplication and compression; and the rise of converged and hyperconverged infrastructure. More recently, cloud-based storage services and virtualization have shaped the development of software-defined and cloud-integrated on-premises storage solutions. Overall, network storage has progressed enormously, from simple file sharing to today’s highly scalable, automated, and resilient storage platforms.
Architecture and Components
The main components of a network storage architecture include servers, storage devices, network connections, and software/protocols. Together, these components allow multiple users and applications to access shared data storage resources over a network (Source).
At the core of the architecture are storage devices such as hard disk drives (HDDs), solid state drives (SSDs), and tape drives. These provide the actual storage capacity and are connected to servers via direct cable connections or through a storage area network (SAN) (Source).
Servers provide the intelligence and management functions, running the network operating system and storage software. Common storage protocols include SMB, NFS, iSCSI, Fibre Channel, FCoE, and NVMe-oF. The network connections tie together the storage devices and servers, typically using high speed Ethernet, Fibre Channel, or InfiniBand (Source).
Additional components like RAID controllers, HBAs, fabric switches, and storage virtualization and replication software help provide redundancy, performance, and data services across the architecture.
Network Attached Storage (NAS)
Network Attached Storage (NAS) is a file storage device connected to a local area network that enables data storage and retrieval from a centralized location for authorized network users and devices. NAS systems contain one or more hard drives and a built-in operating system optimized for file sharing.
NAS provides easy access to data from multiple devices over the network without the need for a separate file server. Files are accessed over standard networking protocols like SMB, NFS, FTP or HTTP. NAS systems appear to users as a regular file server or shared folder.
Some key benefits of NAS include:
- Centralized storage and backup for easier file sharing and protection
- Scalability to add more storage as needed
- No separate dedicated server required
- Accessible from anywhere on the network
Potential drawbacks include:
- Performance limitations compared to SAN
- Individual NAS systems may lack redundancy
- Lower security than DAS
“Intro to Enterprise Data Storage: What is NAS Storage?” explains that the biggest benefit of NAS is easy access to stored data by any networked device. Some vendors also offer remote access (https://solutionsreview.com/data-storage/intro-to-enterprise-data-storage-what-is-nas-storage/).
Storage Area Networks (SAN)
A storage area network (SAN) is a dedicated high-speed network that provides access to block-level storage devices. SANs are primarily used to provide storage to servers so that the servers can access shared pools of storage capacity.
Some key benefits of SAN storage include:
- Centralized storage – SAN provides a centralized pool of storage capacity that can be allocated to servers as needed. This is easier to manage than direct-attached storage.
- Scalability – SANs make it easy to scale storage capacity by simply adding more storage devices to the SAN.
- High performance – SANs utilize fast networking technologies like Fibre Channel, providing high bandwidth and low latency.
- Data sharing – Multiple servers can access the same SAN storage, enabling easy data sharing.
However, there are some potential drawbacks to SAN storage as well:
- Complexity – SANs require specialized networking skills to configure and manage. The complexity also increases failure domains.
- Single point of failure – The SAN network itself is a potential single point of failure. Redundancy must be built in.
- Cost – SAN hardware, software and networking can be expensive compared to other storage architectures.
Overall, SAN provides centralized, scalable and high-performance storage, at the cost of increased complexity and budget requirements. SAN is well-suited for environments that need shared storage with block-level access.
Direct Attached Storage (DAS)
Direct attached storage (DAS) refers to a digital storage system that is connected directly to a computer or server, rather than through a network1. The storage devices in DAS setups, such as hard disk drives (HDDs), solid-state drives (SSDs), or tape drives, are dedicated to a specific server and do not connect to other computers or servers. This makes DAS a simple, high-performing storage solution for individual systems.
Some key benefits of DAS include:
- High speed and low latency since data transfers do not have to go over a network
- Simplicity of setup as no networking is required
- Good performance for data-intensive applications that require fast disk access
- Dedicated storage resources not shared with other systems
However, DAS also has some limitations:
- Limited scalability as storage capacity is restricted to what is inside the server
- No built-in data redundancy since the storage is localized to one system
- Hardware failures can lead to complete data loss without backups
- Storage is not shared or pooled across multiple systems
Overall, DAS works well for standalone servers that need high disk performance but do not require storage networking or sharing. The limited scalability and lack of redundancy make other storage networking options like NAS and SAN more appealing for larger, multi-system environments.
Network Storage Protocols
There are several common protocols used for network storage systems to communicate between servers and storage devices. Some key protocols include:
- Server Message Block (SMB): An application-layer network protocol mainly used for providing shared access to files, printers, serial ports and other resources on a network. It evolved from Common Internet File System (CIFS) protocol and allows applications on computers to read and write to files and request services from server programs over a network. SMB can provide file and print sharing and basic networking capabilities across LANs and WANs. Most SMB implementations support the NetBIOS API for naming services. (Source: https://www.techtarget.com/searchstorage/tip/Choosing-your-storage-networking-protocol)
- Network File System (NFS): A distributed file system protocol that allows servers to access storage over a network similar to how local storage is accessed. NFS allows administrators to mount remote directories that appear similar to local directories. The protocol can be used with NAS devices for file sharing across UNIX and Linux systems. NFS is built on top of IP using Remote Procedure Call (RPC) interface for accessing files over a network. (Source: https://www.parallels.com/blogs/ras/storage-protocols/)
- iSCSI: Internet Small Computer System Interface is an IP-based protocol to establish and manage connections between IP-based storage devices, servers and clients. It allows block-level SCSI data transfer between SCSI storage devices across LANs, WANs or the Internet. This permits location of SCSI storage assets remotely from servers. iSCSI uses TCP/IP for enabling connection and data transfer between iSCSI client called initiator and iSCSI storage device called target. (Source: https://www.techtarget.com/searchstorage/tip/Choosing-your-storage-networking-protocol)
Data Redundancy and Availability
Data redundancy refers to the practice of storing critical data in multiple places to ensure it remains accessible in the event of failure. Redundancy is a key aspect of high availability network storage systems. One common method of providing redundancy is RAID (Redundant Array of Independent Disks), which spreads data across multiple disks. If one disk fails, the data can be reconstructed from the remaining disks.
There are several levels of RAID that provide different mechanisms for redundancy, such as RAID 1 which mirrors data, RAID 5 which uses distributed parity, and RAID 6 which adds an additional parity block. The goal is to maximize availability so that if a component fails, the storage system remains online and accessible. Other methods like clustered storage, replication, erasure coding, and maintaining redundant network paths also provide redundancy.
High availability systems are designed to minimize downtime through built-in redundancy. From redundant power supplies to dual controllers, every component that could cause a failure is duplicated. Storage networks also facilitate redundancy through automated failover between storage nodes.
Ultimately redundancy aims to provide continuous access to data and applications. It enables maintenance, upgrades, and recovery from failures without significant disruption to users and processes that depend on the network storage system.
Security
Securing network storage is crucial to protect sensitive data from unauthorized access and cyber threats. Some key aspects of network storage security include:
Permissions – Most network storage systems allow admins to set up user and group permissions to restrict access to certain files and folders. Effective permission settings prevent unwanted users from accessing, modifying or deleting data.
Encryption – Encrypting data in transit and at rest protects it from being read if intercepted. Many NAS and SAN devices support encryption protocols like SSL/TLS for securing network transfers and AES-256 bit encryption for data at rest on the drives. https://www.buffalotech.com/blog/network-storage-security-best-practices
Securing transfers – Using secure network protocols like SFTP, FTPS and HTTPS for file transfers protects data from man-in-the-middle attacks. Accessing network shares over VPN provides encryption. Disabling unsafe protocols like FTP and CIFS/SMB v1 reduces exposure.
Authentication – Requiring strong passwords and enabling multi-factor authentication prevents unauthorized logins. Centralized authentication via LDAP/Active Directory improves access control.
Monitoring – Auditing user activity and network traffic helps detect suspicious patterns early. Features like change auditing and system logs provide visibility into data access.
Applying security best practices tailored to organizational needs allows enterprises to harness the benefits of network storage while minimizing risk of data breaches.
Trends and Future Directions
Network storage technology continues to evolve to meet the growing data storage needs of organizations. Some key trends shaping the future of network storage include:
Cloud storage – Storing data in the cloud is becoming more prevalent as organizations seek scalable and flexible storage options. Cloud storage allows accessing data from anywhere and reduces the need for on-premises storage infrastructure. Hybrid cloud solutions combine private on-premises storage with public cloud storage for the best of both worlds. According to 2024’s Top 10 Data Storage Trends: A New Era, the global cloud storage market is projected to reach $222 billion by 2028.
Virtualization – Virtualizing network storage infrastructure through technologies like software-defined storage (SDS) and network-attached storage (NAS) virtualization provides more agility and flexibility. Virtualization allows managing and provisioning storage capacity from a centralized interface.
Automation – Automating routine storage administration tasks through policy-based management and artificial intelligence reduces administrative overhead. Automation handles tasks like tiering data between storage tiers, provisioning storage capacity, and optimizing performance.