Persistent Storage Explained

Persistent storage, also called non-volatile storage, refers to any data storage device that retains its data even after power is turned off. Common examples of such devices include:

• Optical media: CDs and DVDs
• Magnetic storage: Hard disk drives (HDDs)
• Solid-state drives (SSDs): These use flash memory and offer faster performance and reliability compared to HDDs.

Types of persistent storage:

• File-based storage: This is the simplest type, where data is organised in named files and folders. It's commonly used for file sharing within organisations.
• Block-based storage: This is common in databases and critical applications needing high performance. It's often used in Storage Area Networks (SANs). Data is divided into fixed-size blocks, offering flexibility for various applications.
• Object-based storage: This stores data as self-contained units called "objects," each with its metadata (data about the data). It's often used for managing large datasets, including structured, semi-structured, and unstructured data, due to its scalability and flexibility.

Persistent storage and containerisation:

Initially, containerised applications couldn't retain data, as it disappeared once the container stopped or was destroyed. To address this, persistent storage volumes were introduced. These volumes allow data to be retained and shared between containers, even if individual containers are recreated. Additionally, ephemeral storage volumes can be used for temporary data that only exists while the container is running.

Additional considerations:

• Network Attached Storage (NAS): This is a dedicated file-level storage device attached to a network, providing shared storage for multiple users and applications.
• Data backup and recovery: Regularly backing up data stored on persistent storage devices is crucial to ensure data protection and prevent loss in case of device failure.

Security considerations:

Implementing robust security measures is essential to safeguard data stored in persistent storage. Encryption methods, access control mechanisms, and data integrity checks are imperative to protect sensitive information and prevent unauthorised access or tampering.

Real-world scenarios:

Consider the following scenarios to illustrate the practical applications of persistent storage:

• A financial institution relies on block-based storage for high-speed transaction processing.
• An e-commerce platform utilises object-based storage to manage vast volumes of product images and customer data.
• A healthcare organisation employs file-based storage for secure sharing of patient records and medical documentation.

In conclusion, understanding the different types and uses of persistent storage is essential for optimising data management and ensuring reliability and security in modern computing environments.