Block Storage

 What is block storage?

Block storage refers to a technology that manages data storage and storage devices. It takes any form of data, such as a file or database entry and divides it into equal sized blocks. These blocks are then stored on physical storage in a way that optimizes quick access and retrieval. Developers often choose block storage for applications that require efficient, fast and reliable data access. Think of block storage as a direct pathway to the data itself. In contrast, file storage involves an additional layer, known as a file system (like NFS or SMB), which must be processed before accessing the data.

What are the advantages of block storage?

Organizations utilize block level storage due to several benefits.

Enhanced Performance

Metadata is extra information that describes the primary data within the storage system. Block storage employs limited metadata but relies on unique identifiers assigned to each block for read/write operations. This reduces unnecessary data transfer and enables servers to efficiently access and retrieve information from block storage. Since block level metadata is minimal, it delivers ultra low latency necessary for high performance workloads—a critical requirement for latency sensitive applications like databases.

For instance, Viasat utilizes Amazon Elastic Block Store (Amazon EBS) to efficiently store and manage high speed data, while also ensuring cost effectiveness. Many organizations rely on Amazon EBS for its ability to enhance performance, optimize costs, facilitate scalability and agility, as well as provide data protection through EBS Snapshots.

Flexibility and scalability

Block storage devices offer versatility in terms of network environments. Individual blocks can be configured to work with different operating systems, such as Windows or Linux. This allows developers to easily share data across various environments, ensuring high availability. The block storage architecture is also designed to scale effectively. Developers have the ability to add new blocks to existing ones in order to meet increasing capacity demands.

Frequent modifications

One of the advantages of block storage is its ability to handle frequent data writes without impacting performance. Instead of rewriting entire files, the system identifies specific blocks that require updates and only modifies those selected blocks with the new data. This makes block storage highly efficient for managing large files that require regular updates.

Granular control

Developers have a great level of control when it comes to storing data on block storage. They can optimize performance by grouping rapidly changing data on specific blocks while storing static files on others. This approach improves overall system performance since ongoing updates only affect a small number of data blocks rather than an entire file. For instance, block storage provides the flexibility for tiering fast changing data on solid state disks (SSD) for optimal performance while storing less frequently accessed warm or cold data on lower cost hard drives (HDD).

 What are the use cases of block storage?

Block storage is widely used for various purposes due to its distinct features. It is particularly favored for transactional, mission critical and I/O intensive applications. Some of the common use cases for block storage include relational or transactional databases, time series databases, containers, boot disks and hypervisor file systems.

Storage networks

Many developers choose to use block storage in the form of a storage area network (SAN). A SAN is a complex network technology that allows multiple systems to access block storage as if it were locally attached devices. Typically, SANs utilize fiber channel connections. In contrast, a network attached storage (NAS) is a single device that serves files over Ethernet.

The SAN architecture consists of three layers;

1. Host layer; This layer comprises the servers responsible for managing storage access.

2. Storage layer; This layer consists of physical block storage devices such as magnetic tape, disk drives or optical media.

3. Fabric layer; The fabric layer acts as a bridge between SAN servers and SAN storage, using components like SAN switches, protocol bridges, routers, cables and gateway devices.

It’s worth noting that SANs incorporate redundancy by employing either synchronous or asynchronous replication across long distances. This helps mitigate downtime in situations where access to a specific geographic location is unavailable.

Moreover, the SAN architecture can support various types of storage within a unified environment, including block storage. Block storage offers an efficient alternative to file based storage in SANs.

Containers

Developers leverage block storage for storing containerized applications on cloud platforms. Containers are software packages that encompass an application along with its resource files for deployment across diverse computing environments.

Block storage offers the same level of flexibility, scalability and efficiency as containers. It allows developers to effortlessly move containers between servers, locations and operating environments without any disruptions.

Transactional workloads

Transactional workloads refer to the data generated during specific points of business processes, such as sales records, operation logs and login alerts. To ensure the efficient storage of these time sensitive and mission critical transactions organizations rely on low latency, high capacity and fault tolerant databases.

Developers utilize block storage to establish a robust and scalable transactional database. By treating each block as a self contained unit, the database can maintain optimal performance even as the amount of stored data increases. Moreover, distributing individual storage blocks across different servers helps prevent access bottlenecks.

In order to ensure data redundancy in critical applications, block storage is protected by a redundant array of independent disks (RAID). This system creates backup copies of data files in secondary storage and can recover them in case of primary disk failure. This approach guarantees uninterrupted application functionality when storing and retrieving transactional workloads using block storage.

Analytics and data warehousing

Block storage also plays a significant role in analytics and data warehousing. When combined with Hadoop’s HDFS architecture (Hadoop Distributed File System), it allows for independent distribution of data units that enhance performance for applications like Hadoop and Kafka analytics.

Virtual machines

Virtual machines (VMs) are another technology that enables computers to run separate operating environments with software defined computing resources.

Let’s say, for instance, you have the option to use a Linux operating system on your Windows desktop by utilizing a virtual machine (VM). A hypervisor acts as a mediator, responsible for managing the necessary memory, storage and computational resources to run the secondary operating environment.

Block storage is compatible with commonly used VM hypervisors. This enables users to install an operating system, file system and other computing resources onto a block storage volume.

In a block storage system, data can be divided into separate fixed size blocks. Each block represents an individual unit of data storage. Complete information, like a data file, is stored across multiple non sequential blocks.

Unlike high level metadata such as file type, ownership and timestamp, the block storage system doesn’t maintain it. To manage the storage of data into respective blocks, developers need to create a data lookup table within the application system. This allows for efficient read/write operations by storing data in different operating environments.

Data Write;

During the writing process, the application divides the data into several sections of block size. It then writes these sections into multiple blocks while keeping track of each block’s identifier in a data lookup table. This enables the server to accurately determine the location of stored data within each block.

Data Read;

When users request a specific file from the block storage system, the server utilizes the data lookup table to locate where different parts of the requested data are stored. The application retrieves these parts from various blocks and combines them in their original order.

Furthermore, apart from block storage, there are additional options available such as object and file storage.

What other types of storage are available?

Different types of storage have their own distinct benefits.

Object storage

Object storage refers to a technology that stores and handles data in an unstructured manner known as objects. Every object is assigned a unique identifier and includes metadata that provides information about the content it holds. For instance, in the case of storing photos, object storage will include metadata such as photographer details, resolution, format and the time it was created.

Comparing Block Storage and Object Storage

Both block storage and object storage have their own advantages depending on the specific use case. Block storage is well suited for scenarios that require low latency and high performance. It proves particularly useful for structured database storage, VM file system volumes and situations with heavy read and write demands. On the other hand, object storage shines when it comes to managing large quantities of unstructured data. It offers benefits such as durability, unlimited storage capacity, scalability and efficient metadata management.

Understanding File Storage

File storage organizes data in a hierarchical structure consisting of files and folders. In network environments, file based storage often utilizes network attached storage (NAS) technology. NAS allows users to access network based data in a manner similar to accessing files on a local hard drive. File storage is user friendly and enables easy management of file sharing controls.

Comparing Block Storage with File Storage

While file storage operates within a specific environment, block storage systems can be integrated with various operating systems seamlessly. File based storage provides an intuitive interface for end users in computing environments. In contrast, block level additions to the block storage system can be made without causing operational latency.

Understanding Instance Storage

Instance store refers to temporary block level storage reserved for your instance. This type of storage is physically attached to the host computer through disks.

Instance storage is perfect for storing temporary information that undergoes frequent changes. It is commonly used for buffers, caches, scratch data and other transient content. It can also be employed to store data that needs to be replicated across a group of instances, like a load balanced collection of web servers.