Repository storage

This section refers to the sizing of standard disk repositories.

Best practice

It’s recommended to use the Veeam Size Estimator (VSE) or Veeam Capacity Calculator to estimate capacity requirements. VSE is useful to build complex scenarios, while the Calculator is more flexible and allows more workloads to be estimated.
Use ReFS/XFS with block cloning to reduce space requirements for synthetic fulls and GFS restore points, and improve merge performance. XFS is more mature and stable and provides better performance and security through data immutability. ReFS is constantly being improved but currently XFS is recommended.
Add more resources if you plan to use health-checks as health checks require additional read I/O.

Estimating repository capacity

When estimating the amount of required disk space, you should know the following:

Total amount of data being backed up
Frequency of backups
Retention period for backups
Planned backup chain type (recommended: Forward Incremental with synthetic full backups)
Is ReFS/XFS block cloning be used (recommended)
The daily change rate, and the yearly growth rate
The forecast period, to address the growth during years

Also, when testing is not possible beforehand, you should make assumptions on compression and deduplication ratios, change rates and other factors. The following figures are typical for most deployments; however, it is important to understand the specific environment to figure out possible exceptions:

Data reduction thanks to compression and deduplication is usually 2:1 or more; it’s common to see 3:1 or better, but you should always be conservative when estimating required space.
Typical daily change rate is between 2% and 5% in a mid-size or enterprise environment. This can greatly vary among servers. Database servers have high change rates (up to 30-50% in worst case). If there is a high percentage of databases involved, calculate with higher values like (e.g. 10%).
Include additional space for one-off full backups.
Include additional space for backup chain transformation — at least the size of a full backup multiplied by 1.25.
- These are not recommended backup chain types, Forward Incremental with Synthetic Fulls is recommended.
- Note: Capacity Tier “Move” only supports Forward Incremental with Synthetic Fulls.
Use ReFS or XFS to improve merge performance and reduce space requirements for synthetic full and GFS through the Fast Clone feature.

Using the numbers above, you can estimate required disk space for any job. Besides, always leave extra headroom for future growth, additional full backups, moving VMs, restoring VMs from tape, etc.

Repository sizing tools that can be used for estimation are available at Veeam Size Estimator (VSE) or Veeam Capacity Calculator.

Note: These are estimation tools and results may differ from a real-life usage scenario.
Note: That both tools only support Forward Incremental and Forever Forward Incremental backup chains. Forever Forward Incrementals can be calculated if ReFS/XFS is enabled as the calculation is the same as with forward incremental with Synthetic Fulls.

Repository storage

Best practice

Estimating repository capacity

References