Data protection strategies are evolving to combat increasingly sophisticated threats like ransomware and accidental deletions. One of the most effective safeguards is immutable backups, which prevent backup data from being altered or deleted for a defined retention period. Veeam Backup & Replication offers robust support for immutability, but implementing it effectively requires careful planning. This article outlines the key technical considerations.
1. Understanding Immutability in Veeam
Immutable backups are backups that cannot be modified or deleted, even by administrators, until the immutability period expires. Veeam achieves this using two primary methods:
- Object Storage Repositories: Many storage systems (Azure Blob, AWS S3) support object lock capabilities. Veeam leverages this to enforce immutability.
- Hardened Linux Repositories: For on-premises deployments, Veeam can create a Linux-based repository with immutable file system permissions, preventing any modification or deletion of backup files during the immutability period.
If using a Hardened Linux Repository on-premise, I would suggest using a physical server or SAN, I know this is not feasible for all cases but is the most secure method as using a VM with virtual disk or using a NAS is not as secure.
2. Storage Considerations
When implementing immutable backups, storage behavior changes compared to standard backups:
- Retention vs. Immutability Period: Even if a retention policy is set to delete older backups, immutable backups cannot be deleted until the immutability period expires. This can temporarily increase storage usage.
- Incremental Backup Chains: Incremental backups are still smaller in size, but Veeam must maintain the chain without breaking immutability rules. Deleting an incremental that is part of an immutable chain is not allowed until the period ends.
- Temporary Storage Spikes: During rotations, storage usage may appear higher, particularly when multiple restore points are retained for immutability.
3. Repository Configuration
a) Object Storage
- Ensure your S3-compatible storage supports Object Lock or WORM (Write Once Read Many) functionality.
- Define an immutability period that aligns with your retention and compliance requirements.
- Verify that Veeam has full access to manage metadata for immutable objects.
b) Linux Hardened Repository
- Deploy a Linux server dedicated to immutable backups, ideally using ext4 or XFS file systems.
- Enable root squash and permission hardening to prevent accidental deletion.
- Veeam creates backups with immutable flags, so even root cannot remove them until the immutability period expires.
4. Backup Job Considerations
- Job Scheduling: Schedule backups to avoid overlapping with repository maintenance or snapshots to prevent write conflicts.
- Incremental Forever Strategy: Works seamlessly with immutability, but be aware that expired incremental backups may remain until the immutability period ends.
5. Performance Implications
While immutable backups do not significantly increase the size of individual backups, certain impacts may occur:
- Write Performance: Immutable object storage may have slightly higher latency due to metadata management.
- Deletion Delays: Old backups are not immediately removed, which may cause temporary spikes in repository usage.
- Resource Planning: Plan for additional repository capacity to accommodate the retention of immutable restore points during peak periods.
6. Compliance and Security
Immutable backups are not just about storage—they are an important part of your ransomware resilience and compliance strategy:
- Regulatory Requirements: Many industries require unalterable backups for defined periods (e.g., financial or healthcare records).
- Ransomware Protection: Immutable backups provide a last line of defense, ensuring that even if production data is compromised, clean restore points are available.
- Access Control: Limit who can create or manage immutable backup jobs to minimize risk.
7. Best Practices
- Align Immutability with Retention: The immutability period should be slightly longer than your retention period to avoid accidental conflicts.
- Monitor Storage Usage: Track repository utilization, especially during backup rotations.
- Test Restores: Regularly perform restore tests to validate backup integrity.
- Use Dedicated Repositories: Avoid mixing mutable and immutable backups in the same repository to simplify management.
- Document Policies: Ensure that your immutability policies and procedures are clearly documented for audits and operational consistency.
Conclusion
Implementing immutable backups with Veeam Backup & Replication strengthens your data protection strategy, providing resilience against accidental deletion and ransomware. However, achieving this requires careful consideration of storage, retention, repository configuration, and operational practices. By understanding the technical implications and following best practices, organizations can maximize the security and reliability of their backup infrastructure.