Immutable Storage: Benefits, Types, and Uses

What Is Immutable Storage? 

Immutable storage refers to a type of data storage where data, once written, cannot be modified or deleted while the immutable storage policy remains in effect. This is useful for protecting data integrity, ensuring that records remain unaltered over time. By implementing immutable storage, organizations can protect their data against unauthorized changes, keeping it as it was originally stored.

This approach is particularly useful in environments requiring rigorous data preservation standards such as financial services, healthcare, and legal sectors. It can also be a strong defense against ransomware attacks by preventing hacker encryption. Immutable storage makes it possible to establish a reliable and compliant storage environment that meets regulatory and corporate governance requirements.

This is part of a series of articles about data backup

In this article:

• Immutable Storage: Benefits, Types, and Uses
• What Is Immutable Storage?
• The Benefits of Immutable Storage
• Types of Immutable Storage
• How Does Immutable Storage Work?
• Immutable Storage and Object Lock
• Immutable Storage for Ransomware Protection
• Limitations of Immutable Storage
• Data Protection and Privacy with Cloudian HyperStore

The Benefits of Immutable Storage 

Using immutable storage can:

• Bolster cybersecurity: Preventing data from being altered or deleted by unauthorized entities. This helps in defending against ransomware attacks where malware attempts to encrypt data. The hacker then demands a ransom to make it accessible. With immutable storage, data remains intact, allowing organizations to maintain secure backups. 
• Prevent human error: Accidental deletions or incorrect data modifications are common causes of data loss. Immutable storage prevents these errors from becoming catastrophic by ensuring data cannot be altered or deleted as long as the immutability policy remains in effect. 
• Ensure regulatory compliance: Regulations such as HIPAA, GDPR, and SOQ impose strict rules on how data should be managed and protected. They mandate the retention and preservation of data for extended periods. Immutable storage solutions help organizations comply with these regulations by providing a secure method that prevents data tampering and deletion, supporting audit processes by ensuring data remains unchanged over time.

Related content: Read our guide to storage management

Types of Immutable Storage 

Immutable storage systems can be deployed on-premises or in the cloud. Cloud-based immutable storage offers scalability and flexibility, allowing organizations to manage storage capacity without substantial upfront investments. These solutions are managed by third-party providers, reducing the internal IT workload and providing access to advanced security technologies. Cloud services often include built-in redundancy and disaster recovery capabilities, ensuring resilience against physical damages at a lower cost than on-premises solutions.

On-Premises

Deployed in the organization’s local data center, these solutions provide full control over the storage infrastructure, useful for organizations with stringent security needs. On-premises immutable storage systems can be tailored to specific requirements and integrate with existing security protocols to protect against data tampering. They typically offer higher performance levels and lower latency compared to cloud-based alternatives.

Air-Gapped

Air-gapping refers to the practice of isolating data storage systems from other networks, particularly the internet, to prevent unauthorized access. For immutable storage, air-gapping can provide an additional security layer by physically distancing backup data from the production environment which is susceptible to attacks.

How Does Immutable Storage Work? 

Immutable storage uses a combination of hardware and software mechanisms to ensure that data, once written, cannot be altered or deleted. This usually involves the following technology components:

• Write Once, Read Many (WORM): In immutable storage, data is written once and can be read multiple times. Once the data is stored, it cannot be modified, overwritten, or deleted within the defined immutability period.
• Retention Policies: Immutable storage systems allow administrators to set retention policies that define how long data should remain immutable. These policies can be time-based (e.g., retain data for 5 years) or event-based (e.g., retain data until a specific event occurs, such as the completion of a project).
• Metadata and Auditing: When data is written to immutable storage, metadata is created to track the data’s origin, timestamp, and other relevant information. This metadata is also immutable and cannot be altered. Auditing mechanisms keep a record of all data access and attempted modifications for security and compliance purposes.
• Secure Storage: Immutable storage systems employ various security measures to protect data from unauthorized access and tampering. These measures may include encryption, access controls, and physical security of the storage devices.
• Data Deletion: Once the specified retention period expires or the defined conditions are met, the immutability constraints are lifted, and the data can be deleted. This deletion process is controlled and audited to ensure compliance with data retention policies.
• Versioning and Snapshots: Some immutable storage systems support versioning, allowing multiple versions of the same data to be stored. Each version is immutable, and users can access and recover specific versions as needed. Snapshots capture the state of data at a particular point in time, providing a consistent and immutable copy for backup or recovery purposes.

Immutable Storage and Object Lock

S3 Object Lock is a feature of the AWS S3 API  that allows you to store objects using a Write Once Read Many (WORM) model. It enables you to protect your data from being deleted or overwritten for a specified period of time or indefinitely.

Key features of S3 Object Lock:

1. Immutability: When an object is locked using S3 Object Lock, it becomes immutable, meaning it cannot be deleted or overwritten by any user, including the root account. This ensures data integrity and protects against accidental or malicious modifications.
2. Retention Modes: S3 Object Lock offers two retention modes:
   • Governance Mode: In this mode, objects can be deleted or overwritten only by users with special permissions. It provides some flexibility for authorized users to manage data.
   • Compliance Mode: This mode provides the highest level of protection. Objects locked in compliance mode cannot be deleted or overwritten by any user, including the root account, until the retention period expires.
3. Retention Periods: You can specify a retention period for objects locked using S3 Object Lock. The retention period can be either a fixed period (e.g., 5 years) or an indefinite period. During the retention period, the object remains immutable.
4. Legal Hold: In addition to retention periods, S3 Object Lock also supports placing a legal hold on objects. When a legal hold is placed, the object becomes immutable until the legal hold is removed, regardless of the retention period.
5. Versioning: S3 Object Lock requires versioning to be enabled on the S3 bucket. When an object is locked, a new version of the object is created, and the lock is applied to that version. This allows you to protect specific versions of objects while still being able to create new versions.

Immutable Storage for Ransomware Protection

Ransomware is a type of malicious software. A common attack vector is to encrypt files until a sum of money (ransom) is paid to the attacker. Once ransomware infects a system, it encrypts the files and displays a message demanding payment, usually in cryptocurrency, in exchange for the decryption key. Some variants of ransomware not only encrypt files but also threaten to release sensitive data publicly if the ransom is not paid.

Immutable storage can be an effective defense against ransomware attacks by safeguarding the integrity and availability of critical data. Here’s how:

1. Prevents data encryption: Since immutable storage ensures that data cannot be modified or deleted once written, ransomware cannot encrypt the stored data. This means that even if the system is infected, the critical data remains accessible in its original, unaltered state.
2. Ensures data recovery: In the event of a ransomware attack, organizations can rely on immutable backups to restore their systems. These backups are protected from alteration, ensuring that the organization can quickly recover its data without paying the ransom.
3. Supports incident response: Immutable storage allows organizations to maintain a clean and unchangeable copy of their data. This helps in incident response by providing a reliable baseline for forensic analysis, identifying the extent of the compromise, and supporting recovery efforts.
4. Reduces operational downtime: By having an immutable copy of critical data, organizations can reduce the downtime associated with a ransomware attack. They can quickly restore operations by accessing unaltered data, minimizing the impact on business continuity.
5. Compliance and legal safeguards: For industries that must comply with strict data retention and integrity regulations, immutable storage ensures that data remains untampered even during a ransomware attack. This helps organizations avoid penalties and meet legal requirements while recovering from the attack.

Limitations of Immutable Storage 

Organizations should also be aware of the limitations of immutable storage:

• Cost: The inflexibility of not being able to modify or delete data can lead to increased storage costs, as new data must be continuously added without the option to remove outdated or irrelevant information until the retention period has expired. This requires careful capacity planning and management to prevent overhead costs from escalating.
• Not sufficient for data protection: While immutable storage guarantees data integrity, it does not inherently protect against all forms of data loss. For example, physical damage to storage devices or systemic failures could still result in data loss. Backup strategies and disaster recovery plans are still needed to complement the immutability feature.
• Complexity: Implementing and managing immutable storage systems require specialized knowledge and resources. Organizations must ensure that staff are adequately trained and that procedures align with the technologies used in immutable storage solutions to fully leverage their benefits and mitigate associated risks.

Data Protection and Privacy with Cloudian HyperStore

Cloudian is a leading provider of object storage solutions that enable organizations to store, manage, and protect large amounts of unstructured data. With a focus on scalability, flexibility, and security, Cloudian’s HyperStore platform provides a foundation for enterprises and service providers to build their data storage infrastructure. 

Cloudian has been at the forefront of supporting data immutability, recognizing its critical importance in ensuring data integrity and compliance. Through its integration with AWS S3 Object Lock API, Cloudian enables customers to create immutable data backups that are protected against accidental or malicious deletion, modification, or ransomware attacks. 

This immutability feature, combined with Cloudian’s scalability and cost-effectiveness, makes it an ideal solution for organizations seeking to safeguard their data while leveraging the benefits of object storage.

Learn more about data protection with Cloudian.