- Veeam Support Knowledge Base
- Best Practices for Microsoft Data Deduplication
Best Practices for Microsoft Data Deduplication
| KB ID: | 2023 |
| Product: | Veeam Backup & Replication |
| Published: | 2015-04-22 |
| Last Modified: | 2026-01-13 |
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Purpose
This article documents Best Practices, Limitations, and Considerations relating to the use of storage that has Microsoft Windows Deduplication enabled when storing backup files created and managed by Veeam Backup & Replication.
Considerations and Recommendations
- [CRITICAL] Veeam strongly recommends that all Microsoft Data Deduplication tasks be scheduled to operate when Veeam jobs are not operating, as Microsoft Data Deduplication tasks can and will interfere with Veeam backup file creation and manipulation operations.
- Microsoft recommends that "Optimally, Data Deduplication should have 1 GB of memory for every 1 TB of logical data. For instance, if you are optimizing a 10 TB volume, you would optimally need 10 GB of memory allocated for Data Deduplication (1 GB * 10). This ratio will ensure the maximum performance for Data Deduplication jobs."
- When using a Windows-based repository with a ReFS volume, native Microsoft ReFS Deduplication should not be used. The ReFS Deduplication included with Microsoft Server 2025 utilizes the same block cloning technology as Veeam's Fast Clone technology; therefore, there is little to no benefit to enabling Microsoft ReFS Deduplication, and it may lead to performance degradation.
- Veeam recommends that the MinimumFileSize value be set to prevent Microsoft Data Deduplication from causing file locks on smaller metadata (vbm,vacm,vasm) files associated with restore point creation.
PowerShell example command:
Adjust volume letter as needed.
# This value configures Data Deduplication to not optimize files smaller than 256MB. Most .vbm files are much smaller, but this size should be sufficient to cover even the largest environments metadata files.
Set-DedupVolume -Volume V: -MinimumFileSize 268435456Additional Best Practice Information
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