In the realm of data center storage solutions, understanding the intricacies of expansion methods is paramount. Effective storage is crucial for managing the growing volumes of data and ensuring secure, efficient access. As data centers evolve, reliable and flexible storage options are essential to meet the ever-changing demands of businesses. With this foundation, this article will start with traditional storage systems and move towards distributed storage fundamentals and their diverse applications.

Direct Attached Storage

Direct Attached Storage (DAS) refers to storage devices directly connected to a server, utilizing interfaces like SATA, SAS, and USB. It offers cost-effective and simple installation, with good performance for applications like operating systems and databases. However, DAS has limited scalability and challenges in resource sharing among servers. Additionally, server failures can impact storage access, highlighting the need for careful consideration in its implementation.

Centralized Network Storage

Unlike DAS, NAS and SAN storage is networked storage, where NAS has its own file system that can be accessed and used directly through a PC, while SAN does not have its own file system, but has dedicated switches that provide storage services to servers over a dedicated network.

• NAS

NAS (Network Attached Storage) is a specialized storage server designed to provide file-level data access over a network. Connected through Ethernet, it enables access via protocols such as NFS and CIFS/SMB. NAS offers centralized management, facilitating easy sharing and good scalability for storage needs. However, compared to DAS, NAS typically incurs a higher cost. Furthermore, its performance is susceptible to network conditions, which can affect data access speeds. Despite these drawbacks, NAS remains a popular choice for organizations seeking efficient and centralized file storage solutions.

• SAN

SAN (Storage Area Network) is a high-speed dedicated network designed to facilitate block-level data access, primarily tailored for enterprise-level applications. SANs typically utilize advanced technologies like Fiber Channel (FC) or Ethernet, establishing connections between servers and storage devices via protocols such as FC-SAN or iSCSI. These networks offer numerous advantages, including high performance, scalability, and suitability for large-scale data storage and mission-critical applications. SANs also support data redundancy and robust disaster recovery mechanisms. However, the implementation of SANs comes with notable drawbacks, such as high initial costs, complex configuration and management requirements, necessitating specialized knowledge and technical support throughout their lifecycle.

In summary, DAS is like a large-scale portable hard drive, suitable for small environments or personal use; NAS is a storage device within a network, ideal for small businesses or households requiring file sharing capabilities; SAN is a network within storage devices, designed for high-performance, high-availability storage solutions for large enterprises and data centers.

Basics of Distributed Storage

From the organization structure of storage, storage can be divided into three types: direct attached storage (DAS), centralized network storage (NAS and SAN), and distributed network storage. Next, we will explore distributed storage in detail, examining its core principles, advantages, classifications and applications.

Distributed storage is a data storage architecture that disperses data across multiple independent physical storage devices (nodes) over a network, rather than centrally storing it on a single or a few devices like traditional storage. This technology is designed to enhance the scalability, performance, reliability, and efficiency of storage systems. Consequently, it is particularly suitable for handling large-scale data storage and access requirements.

Advantages of Distributed Storage

Distributed storage systems offer numerous benefits that make them a preferred choice for modern data storage needs, especially in large-scale and geographically dispersed environments. Here are some of the key advantages:

• Reliability and Redundancy: These systems typically replicate data across multiple nodes, ensuring that even if one node fails, the data can still be retrieved from another node. This replication enhances the reliability and availability of the data. Additionally, distributed storage systems are designed to be fault-tolerant, allowing them to continue operating smoothly even in the event of hardware failures. For instance, if a data center is rendered inoperative due to a natural disaster, other data centers can still provide data access services, ensuring continuous availability.
• Scalability: Distributed storage systems can easily expand storage capacity by adding nodes, an approach known as horizontal scaling. In contrast, centralized systems need to expand by adding capacity to individual storage devices, known as vertical scaling, which is typically less efficient and more costly. In addition, distributed storage systems can balance workloads across multiple nodes, preventing a single node from becoming a performance bottleneck. This scalability makes distributed storage suitable for a wide range of needs, from small businesses to large-scale Internet services.
• Cost Efficiency: Distributed storage systems often utilize commodity hardware, which is more economical than specialized storage solutions. This reduces hardware costs and allows organizations to build large-scale storage systems using affordable equipment.
• Improved Disaster Recovery: By storing data in multiple locations, these systems are better protected against natural disasters, power outages and other localized disruptions. Cloud storage providers typically back up data in different geographic locations to ensure high availability and security.

In summary, distributed storage represents a powerful and versatile solution for modern data management, offering significant advantages in reliability, scalability, cost efficiency, and disaster recovery. These advantages make it an essential component of enterprise storage architectures, capable of meeting the diverse needs of today’s data-driven organizations.

Classification of distributed storage

Based on the characteristics and requirements of different scenarios, distributed storage products can be classified into four main categories based on storage objects, product forms, storage mediums, and deployment methods.

• Classification by storage object

In terms of storage objects, it includes distributed block storage, distributed file storage, distributed object storage, and distributed unified storage. Distributed block storage examples include Ceph and vSAN, while distributed file storage examples are Ceph, HDFS, and GFS. Distributed object storage, such as Ceph and Swift, is designed for handling unstructured data like text, audio, and video. Distributed unified storage supports block, file, and object storage, catering to the diverse needs of virtualization, cloud, and container platforms.

• Classification by product form

When it comes to product forms, distributed storage can be delivered as appliances, pure hardware, or pure software. Appliances integrate hardware and software for high compatibility and performance. Pure hardware solutions, such as disk arrays and flash clusters, offer reliable storage for sensitive data. Pure software solutions provide customized application software and platform licenses, ideal for optimizing existing storage hardware in legacy data centers.

• Classification by storage medium

Regarding storage mediums, distributed storage can be all-flash or hybrid. Distributed all-flash storage, composed entirely of SSDs, offers exceptionally high read and write speeds, making it suitable for performance-intensive applications. Distributed hybrid flash storage combines SSDs and HDDs, balancing cost and performance, and is currently the mainstream choice for many enterprises.

• Classification by deployment method

Deployment methods for distributed storage include virtualization integration, container integration, and separation. Virtualization integration involves deploying storage and server virtualization on the same hardware node, simplifying architecture and reducing costs. Container integration is designed for environments like Kubernetes, offering seamless integration and efficient resource management. Lastly, the separation method keeps storage nodes and applications distinct, allowing flexible adaptation to different computing environments and ensuring scalability and performance for large-scale data storage needs.

Mainstream Technologies in Distributed Storage

• Ceph

Currently, the most widely used distributed storage technology, Ceph, is the result of Sage’s doctoral studies, published in 2004 and subsequently contributed to the open-source community. It has garnered support from numerous cloud computing and storage vendors. Supporting object storage, block device storage, and file storage, it demands high technical proficiency in operations and maintenance. During Ceph expansion, its characteristic of balanced data distribution may lead to a decrease in overall system performance.

• GPFS

Developed by IBM, GPFS is a shared file system, and many vendor products are based on it. It is a parallel disk file system that ensures all nodes within a resource group can access the entire file system in parallel. GPFS consists of network shared disks (NSD) and physical disks, allowing clients to share files distributed across different nodes’ disks, resulting in excellent performance. GPFS supports traditional centralized storage arbitration mechanisms and file locking, ensuring data security and integrity, which other distributed storage systems cannot match.

• HDFS

HDFS (Hadoop Distibuted File System), a storage component of the Hadoop big data architecture, is primarily used for storing large data. It employs multi-copy data protection, suitable for low write and multiple read businesses. It has high data transfer throughput but poor data read latency, making it unsuitable for frequent data writes.

• GFS

Google’s distributed file storage system, designed specifically for storing massive search data. The HDFS system was initially designed and implemented based on the concept of GFS (Google File System). Similarly suitable for large file read/write operations, it is unsuitable for small file storage. Ideal for processing large-scale file reads, requiring high bandwidth, and insensitive to data access latency for search-like businesses.

• Swift

Swift is also an open-source storage project primarily oriented towards object storage, similar to the object storage service provided by Ceph. It is mainly used to address unstructured data storage issues, targeting object storage businesses that require high data processing efficiency but low data consistency. In OpenStack, the object storage service uses Swift rather than Ceph.

• Lustre

An open-source cluster file system based on the Linux platform, jointly developed by HP, Intel, Cluster File System, and the U.S. Department of Energy, formally open-sourced in 2003, mainly used in the HPC supercomputing field. It supports tens of thousands of client systems and can support PB-level storage capacity, with a single file supporting a maximum of 320TB capacity. It supports RDMA networks and optimizes large file read/write fragmentation. It lacks a replica mechanism, leading to single points of failure. If a client or node fails, the data stored on that node will be inaccessible until it is restarted.

• Amazon S3

Amazon S3(Simple Storage Service) is a cloud storage service provided by Amazon and belongs to distributed object storage. It allows users to store and retrieve any amount of data and provides high reliability and durability. It is widely used in backup, archiving, static website hosting, and other fields.

• GlusterFS

GlusterFS is a scalable distributed file system that supports distributed data volumes and can store data across multiple servers. It adopts decentralized architecture, providing high availability and performance, suitable for large file storage and content distribution.

Applications of Distributed Storage

In the realm of modern technology, distributed storage has emerged as a pivotal solution, catering to a diverse array of needs across various sectors. Here’s how distributed storage is transforming data management:

• Cloud Storage: At the core of cloud service providers, distributed storage facilitates elastic scalability and ensures data isolation and security in multi-tenant environments.
• Big Data Analytics: Powering platforms like Hadoop with HDFS, distributed file systems enable the storage and processing of massive datasets, supporting large-scale data analytics.
• Containerization and Microservices: With tools like Kubernetes, distributed storage offers persistent storage volumes, ensuring data persistence across containerized environments, vital for container orchestration and microservices architecture.
• Media and Entertainment: Meeting the high-throughput and large-capacity demands of media storage and streaming services, distributed storage solutions excel in scenarios requiring seamless handling of multimedia content.
• Enterprise Backup and Archiving: Leveraging its high scalability and cost-effectiveness, distributed storage emerges as an ideal choice for enterprise backup and long-term data archiving, ensuring data integrity and accessibility over extended periods.

In essence, distributed storage applications are revolutionizing data management practices, offering unparalleled scalability, resilience, and efficiency across a spectrum of industries.

Summary

In the rapidly evolving landscape of data centers, the shift from traditional storage systems to distributed storage solutions has become increasingly pivotal. This article explores the foundational knowledge of distributed storage, including its concepts, advantages, and classifications. We delve into mainstream technologies driving this innovation and highlight their diverse applications across various industries.

As a leading technology company specializing in network solutions and telecommunication products, FS leverages advanced distributed storage to enhance data center operations, offering scalable and efficient solutions tailored to modern enterprise needs. Join us to explore further insights and knowledge, and discover our range of storage products.