[Free Upcoming Webinar] Every vendor is simple… until they’re not! Learn why Mirazon loves Ootbi’s simplicity >>>

Immutable Backup and Immutable Storage: All You Need to Know

In the face of devastating data loss and cunning cyber threats, the non-negotiable need for rock-solid data protection is crucial. At Object First, we firmly believe that immutability is the safest data storage and backup approach for businesses, empowering them to safeguard their valuable information, especially against the growing threat of ransomware attacks.

Let’s find out what an immutable backup and immutable storage are, why they protect against ransomware, and how you can achieve immutability.

What Is Immutable Backup?

An immutable backup is a secure data copy that cannot be altered or deleted, providing robust protection against modifications or deletions. It employs an advanced ‘object lock’ mechanism that effectively prevents unintentional or deliberate alterations or deletions for a specified duration, as the backup creator chose.

Unlike conventional backups that may be susceptible to changes, immutable backups create unchangeable copies of your valuable data, offering an ironclad shield against accidental or malicious modifications.

During this immutable state, the data utilizes WORM protection, meaning it becomes ‘write once, read many,’ allowing multiple accesses while remaining impervious to overwriting.

What Is Immutable Storage?

Immutable storage is a type of data storage where the stored information cannot be modified, deleted, or overwritten once it has been written.

It ensures that files remain stable and unchanged in the data storage context, which makes it an ideal solution for storing critical business data such as legal documents, financial records, and healthcare records.

How Does It Work?

When data is stored in an immutable storage system, it is written to the storage medium using a unique identifier that cannot be altered or overwritten. Each piece of data is assigned a unique identifier to verify its integrity and authenticity. This identifier ensures that the data remains unmodified and unchanged throughout its lifecycle.

Immutable storage systems employ various technologies to ensure the security and protection of stored data. For example, some systems use advanced encryption algorithms to protect data at rest, while others use access controls to prevent unauthorized access to the data. Additionally, most immutable storage systems integrate with backup and disaster recovery solutions to provide redundancy and availability.

Overall, immutable storage is a powerful tool for mid- and large-enterprise organizations that must store data for long periods while ensuring its protection and integrity.

Does Immutable Backup Protect Against Ransomware?

Ransomware attacks have emerged as a major cybersecurity threat, often leaving victims grappling with encrypted data and the unsettling demand for a ransom.

When ransomware strikes, it attempts to encrypt data, making it inaccessible until a ransom is paid. However, with the protection of immutable backup, the stored data becomes write-protected, thwarting the ransomware’s attempts to modify or delete critical information.

Even in the unfortunate event of successful ransomware encryption, the original unencrypted data remains secure and unaffected within the immutable backup. This key advantage allows businesses and individuals to restore their data to its pre-attack state without giving in to the attackers’ demands.

Immutable Backup vs. Mutable (or Traditional) Backup

Immutable backup solutions leverage WORM technology to ensure that data stored in the backup remains impossible to alter, with a strict ‘read-only’ policy. It empowers immutable backups with superior security measures compared to traditional tools, which rely on media that can be overwritten, making it susceptible to changes.

The enhanced data retention capability of immutable backup also sets it apart from standard solutions, allowing for more prolonged preservation of critical information. However, this benefit can become a drawback when non-essential data is kept for extended periods.

On the other hand, traditional backup solutions offer more flexibility with customized backup frequency and control over scheduling, while immutable backups operate automatically, ensuring dependable data protection.

Plus, immutable backups entail higher implementation costs due to specialized hardware and software requirements, while conventional backups are more cost-effective initially.

Immutable Backup With 3-2-1 and 3-2-1-1-0 Backup Rules

In data protection, the principles of the 3-2-1 backup rule and its extended variation, the 3-2-1-1-0 backup rule, hold utmost importance.

These fundamental practices complement and enhance the concept of immutable backup, creating a robust foundation for data security and recovery.

The 3-2-1 Backup Rule

The 3-2-1 backup rule revolves around three critical components for adequate data protection:

  1. Three Copies: Keep at least three copies of your data, the primary copy, and two backups. This redundancy ensures data resilience, allowing recovery even if one copy is compromised.
  2. Two Storage Media Types: Diversify data storage using two different media types, for example, store data on a local hard drive, external device, or network-attached storage (NAS).
  3. One Off-Site Backup: Maintain one copy of data off-site, separate from the primary and secondary backups. This off-site backup can be in the cloud, on a remote server, or stored physically at a different location.

The 3-2-1-1-0 Backup Rule

The 3-2-1-1-0 backup rule enhances data security with two additional components:

  1. One Extra Copy: Maintain an extra copy offline, air-gapped, or immutable, bolstering backup reliability and protection against threats, providing peace of mind.
  2. Zero Errors Upon Backups: Ensure data copy integrity and reliability, instilling confidence in their storability for smooth recovery.

Implementing Immutable Backups or How to Achieve Data Immutability

There are several ways to achieve immutability with immutable backup and storage, including WORM media, object storage, and vendor-specific or vendor-created immutability.

WORM Media

WORM technology ensures data cannot be modified or deleted once written, making it an effective way to achieve immutability. However, it can also be used for digital storage systems.

  • WORM Tape. Write-once-read-many tape storage is affordable for companies looking to implement immutable storage. Data is written to tape sequentially, making it difficult for cybercriminals to modify or delete specific data.
  • Cloud WORM. Provided by cloud storage providers with easy data access (examples are Amazon S3 Glacier and Microsoft Azure Blob Archive). Requires no physical storage space, but costs may increase over time. Important note: It’s the best and least expensive storage for long-term retention and archivable, but you need to confirm with the vendor if it’s WORM.
  •  WORM Disk. It is an example of true WORM technology with read-only disks, but this is consumer-level (B2C-level) technology, not B2B, because of low capacity.

Object Storage

Object storage stores data as objects rather than files or blocks. The things can be stored in a distributed system, allowing for redundancy and increasing availability. This type of storage can achieve immutability by setting a policy on the objects that prevents their deletion or modification. Once written, the thing cannot be changed or deleted, ensuring its integrity. Object storage is a scalable, cost-effective solution for businesses that store large amounts of unstructured data.

  • Object Storage can be Cloud as AWS, Azure or
  • On-premise as Ootbi by Object First, Scality, Cloudian, Pure Storage, Dell ECS, Netapp StorageGrid, IBM, MinIO.
  • Most of the on-premises object storage and the cloud are S3-compatible, and the S3 protocol has built-in immutability. However, other examples of object storage, such as Azure, are not S3-compatible but still provide immutability. S3-compatible clouds are AWS (they invented it), Wasabi, Backblaze, and DigitalOcean. S3-compatible on-premise are Ootbi, Scality, Cloudian, Pure Storage, Dell ECS, Netapp StorageGrid, IBM, MinIO.

For other vendors, it might or might not have immutability.

Vendor-Specific or Vendor-Created Immutability

  • The read-only volume snapshots technique involves creating an unchangeable copy of a data set stored on a volume at a specific time. Once the snapshot is taken, it is marked as read-only, meaning the data it contains cannot be modified or deleted without affecting the original volume.
  • The file immutability technique marks a file as read-only or unchangeable once created. The file’s contents cannot be modified, deleted, or overwritten without the appropriate permissions or credentials, even if they have write access to the file system.
  • Veeam Hardened Linux repository is an example of vendor-created immutability where the file immutability technique is used. These repositories have strict access controls, limited attack surface, no root access, and auditing mechanisms, making them ideal for preserving data integrity.

Benefits of Immutable Backup and Immutable Storage

Immutable backup built on immutable storage offers numerous benefits to businesses and individuals. By locking data into an unchangeable state, immutable storage provides several security and availability benefits that are not available with traditional storage solutions.


Immutable storage and immutable backup are read-only, which means that once data is written, it cannot be modified or deleted. This benefit makes it an ideal solution for storing sensitive data that must be preserved in its original state.

Can’t Be Encrypted by Ransomware

Ransomware attacks have become an increasingly common threat to businesses and individuals. By encrypting data and threatening to delete it unless a ransom is paid, attackers can cause significant damage to organizations. However, with immutable backups based on storage, ransomware attacks are less effective since the data cannot be modified or deleted.

Can’t Be Deleted

In addition to protecting against ransomware, immutable backup based on immutable storage protects against accidental deletion or data loss. Since the data cannot be deleted, it is always available and accessible when needed. Backups that are not possible to delete are also called indelible.

Improves Data Availability

With immutable storage, data is always available and accessible because it is stored in a way that ensures its integrity and availability, even in the event of hardware or software failures.

Maintains Data Authenticity

Immutable storage provides a mechanism for ensuring data authenticity by employing cryptographic hashes. These hashes verify that the data has not been tampered with or altered. With immutable storage, you can be confident that your data is authentic and has not been compromised.

Why Do Mid- and Large-Enterprises Need Immutability?

Enterprises generate and store an enormous amount of data, from customer information to financial records and internal communications. As the volume of data grows exponentially, businesses face the challenge of ensuring it is secure and protected from loss or corruption. It is where immutable storage for backup comes in.

Immutable storage refers to unchangeable data that cannot be deleted or modified once written. It means that even if cybercriminals gain access to the system, they cannot alter or delete important data. In the event of an attack, the enterprise can restore its data to its last known good state and continue operations without significant downtime or cost.

In short, immutable storage and immutable backup protect against cyber threats, help enterprises meet compliance requirements, and save money in the long run. Investing in these solutions is a necessary choice for any business that values its data and wants to ensure the continuity of its operations.

Immutable Backup With Ootbi

Ransomware-proof and immutable out-of-the-box, Object First Ootbi delivers secure, simple, and powerful backup storage for mid-enterprise Veeam customers that can be racked, stacked, and powered in 15 minutes while providing unbeatable backup and recovery performance.

With a hardened operating system ensuring data integrity and zero configuration required, Ootbi offers a seamless and confidence-inspiring backup solution, ready to safeguard your critical data the moment it’s deployed.


Embracing immutability and utilizing immutable backups and storage is paramount in securing critical data and protecting against various dangers.

With unchangeable data, enhanced data integrity, and resistance to ransomware, businesses can ensure the availability and authenticity of their information. Implementing the 3-2-1 and 3-2-1-1-0 backup rules further fortifies data protection, providing a robust data security and recovery foundation.

Elevate your immutable backup protection with Ootbi by Object First. Learn how Ootbi can protect your data from cyber threats, disasters, and accidental deletion by booking a free online demo!


What Is an Indelible Backup?

Indelible backup, synonymous with immutable backup, ensures data cannot be modified, deleted, or overwritten once written. While some vendors may use the term “indelible backup,” the industry predominantly refers to it as “immutable backup.”

What’s the Difference Between Air-Gapped and Immutable Backup?

Air-gapped backup involves physically disconnecting a storage medium from the network, protecting it from malware and ransomware. While both methods aim to safeguard data from tampering, immutable backup offers more comprehensive protection by ensuring data remains unmodifiable and unerasable, regardless of storage location or access privileges.

What Is an Immutable Infrastructure?

Immutable infrastructure entails servers that remain unmodifiable, unedited, or deleted after deployment. Instead of updating existing servers, users must create new ones with desired changes, setting them apart from mutable servers that allow alterations after initial deployment.

Are There Any Disadvantages of Immutable Backups?

Although immutable backups have many advantages, it is important to recognize and consider their possible weaknesses. Storing undeletable data long-term may escalate costs, as immutability doesn’t protect against physical storage damage or loss. Regular on-site testing is vital for data integrity, while advanced ransomware with sleeper attacks or trojan horses could pose risks to immutable backups.

What is the recommended frequency for updating immutable backups?

Maintaining a backup that reflects the latest production is essential for quick and efficient data restoration during an attack or corruption. Organizations should assess how frequently their critical data changes and how much data loss is acceptable in case of a breach or loss, ensuring regular testing of backups to keep confidence in data availability and currency.

Book a Free Online Demo!

Request a Demo