Immutable Backups: Why You Need Them and How They Work

What Are Immutable Backups?

Immutable backups refer to a kind of data backup that cannot be modified or deleted once they have been written. The term “immutable” comes from the Latin word “immutabilis”, which means unchangeable. It’s a concept that has its roots in the world of databases and data structures, but has now found its way into the realm of data protection and backup. Once an immutable backup is created, it remains in its original state, untouched and unaltered, until a predetermined retention period has expired.

The crucial characteristic of an immutable backup is its resistance to change – it cannot be altered, edited, or deleted by anyone or anything, including the system that created it. This is enforced through a combination of software controls and hardware design. These backups are typically stored on a medium that is physically incapable of modification, such as write-once-read-many (WORM) storage.

Immutable backups are designed to provide a safeguard against data loss. In a world where data is increasingly valuable – and increasingly vulnerable – robust, reliable backups are critical. The immutability of these backups ensures that they can serve as a trusted source of recovery in the event of data loss or corruption.

In this article:

• Immutable Backups: Why You Need Them and How They Work
• What Are Immutable Backups?
• Why are Immutable Backups Important?
  • Protection Against Ransomware and Malware Attacks
  • Ensuring Data Integrity and Compliance
  • Role in Disaster Recovery Strategies
• Immutable Backup vs. Traditional Backups
• How Does Immutable Backup Work?
• Best Practices in Managing Immutable Backups
  • Regular Backup Scheduling
  • Retention Policy Management
  • Test Restore Processes Regularly

Why are Immutable Backups Important?

Protection Against Ransomware and Malware Attacks

One of the biggest threats to data today comes from cyberattacks, specifically ransomware attacks. These attacks can infiltrate a system, encrypt data, and demand a ransom for its release. In many cases, even if the ransom is paid, there’s no guarantee that the data will be recovered.

This is where immutable backups come into play. Because they can’t be modified or deleted, they are immune to these types of attacks. Even if a ransomware or malware attack manages to infiltrate a system and encrypt the data, the immutable backup remains untouched, providing a reliable source for data recovery.

Ensuring Data Integrity and Compliance

Data integrity refers to the accuracy and consistency of data over its entire lifecycle. Maintaining data integrity is crucial for accurate decision-making. immutable backups help ensure data integrity by preserving an unalterable record of data, which can be used to verify the accuracy and consistency of other data.

In addition to ensuring data integrity, immutable backups also play a crucial role in compliance. Many industries and jurisdictions have strict regulations regarding data preservation and protection. immutable backups can help organizations meet these regulatory requirements by providing a verifiable and unalterable record of data.

Role in Disaster Recovery Strategies

Immutable backups are also a critical component of any comprehensive disaster recovery strategy. In the event of a disaster – whether it’s a natural disaster, a hardware failure, or a cyberattack – immutable backups provide a reliable source for data recovery. This assumes, of course, that the immutable backups are stored separately from production systems.

Because they can’t be modified or deleted, immutable backups aren’t susceptible to the same risks as other data. This means that in the event of a disaster, organizations can rely on their immutable backups to recover their data and resume operations as quickly as possible.

Immutable Backup vs. Traditional Backups

The main difference between immutable backups and traditional backups lies in the level of protection they offer. While traditional backups can be a useful tool for data recovery, they are not immune to the risks of modification or deletion. Whether it’s a result of human error, a system glitch, or a cyberattack, traditional backups can be altered or deleted, rendering them useless in the event of data loss.

Immutable backups, on the other hand, can’t be modified or deleted, so they provide a reliable source for data recovery, regardless of the cause of data loss. This makes them a critical tool for any organization that needs to safeguard valuable data.

How Does Immutable Backup Work?

Immutable backups are typically achieved through a combination of locking mechanisms like write-once-read-many (WORM) technology, strong encryption, and stringent access controls, which collectively ensure the data remains in a non-modifiable state.

Here are the main types of immutable backup technologies:

• WORM backup: This solution creates a non-erasable copy of your data on media like CDs, DVDs, or magnetic tapes. After data is written to these media, it becomes read-only. WORM is primarily used for long-term archiving of sensitive data​​.
• Continuous Data Protection (CDP): CDP continuously backs up data, providing up-to-date restoration of data changes. It copies changes made in primary storage to backup storage automatically, ensuring the most recent state of data is always available​​.
• Time-based snapshots: These are taken at specific intervals using a delta algorithm, recording only the changes that occurred since the last backup. This method is ideal for systems with many virtual machines and facilitates quick data restoration​​.
• Cloud storage-based immutable backup: Utilizes remote cloud servers for storing backups, ensuring data accessibility from anywhere. This solution is scalable and offers features like encryption and multi-factor authentication. It often operates on a pay-as-you-go pricing model​​.

Some solutions incorporate blockchain technology to provide an extra layer of authenticity. Each backup event is stored as a block within a cryptographically linked chain, offering a clear, tamper-proof record of data history.

Another advanced feature of immutable backup solutions is chain-of-custody tracking. This approach registers every data transaction and creates a detailed audit trail. This trail is crucial in tracing any unauthorized changes or breaches, thereby enhancing security against potential cyber threats.

Related content: Read our guides to backup storage and backup cloud storage

Best Practices in Managing Immutable Backups

Here are a few best practices you can use to make the best use of immutable backups in your organization.

Regular Backup Scheduling

One of the most important aspects of managing immutable backups is ensuring that backups are taken regularly. This is because the data in an immutable backup is a snapshot of the data at a particular point in time. If backups are not taken frequently, the data may become outdated and not accurately reflect the current state of the system.

The frequency of backups will depend on the specific needs of the organization. For some, daily backups may be sufficient. For others, particularly those with high volumes of data or high rates of change, more frequent backups may be necessary.

Retention Policy Management

Another critical aspect of managing immutable backups is the management of retention policies. Because the data in an immutable backup cannot be altered or deleted until a predetermined period of time has passed, it is important to carefully manage how long backups are retained.

The length of time that backups should be retained will depend on a variety of factors, including the nature of the data, regulatory requirements, and the organization’s risk tolerance. In general, however, backups should be retained for as long as they may be needed to restore the system in the event of a data loss event.

Test Restore Processes Regularly

Regular testing of restore processes is another key practice in managing immutable backups. Because the data in an immutable backup is a snapshot of the data at a particular point in time, it is important to ensure that the data can be restored accurately and completely.

Testing restore processes involves performing a mock restoration of the data from the backup and then verifying that the restored data is correct and complete. This process should be performed regularly to ensure that the restore process is working as expected and to identify any potential issues before they become a problem.

The security of encryption keys is another critical aspect of managing immutable backups. If the keys used to encrypt the data are lost or compromised, the data may become inaccessible.

Immutable Data Storage with Cloudian

Cloudian HyperStore is an on-prem, enterprise storage solution that protects your data with S3 Object Lock which provides government-certified data immutability. HyperStore is hardened by the use of HyperStore Shell (HSH) and RootDisable, securing the solution at the system level, even disabling root access to make the solution impregnable.

Cloudian uses a fully distributed architecture to eliminate single points of failure, and enable easily scalability from hundreds of Terabytes to Exabytes. It is cloud native and fully compatible with the Amazon S3 API.

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