Veeam Backup Size Calculator

Calculating the required disk space for Veeam backup copies can be a complex task. With so many variables to consider, it's no wonder that finding a definitive way to calculate storage requirements has proven elusive. In this article, we'll explore some of the key factors that affect backup size and provide a formula to help you estimate your storage needs.

Understanding Veeam Backup Components

Before diving into the calculations, it's essential to understand the different components involved in a Veeam backup:

* Restore Points (RP): These are full backups created according to the retention policy. For example, if you set a 12-month retention period, you'll have 15 restore points.

* GFS (Grandfather-Father-Son): This is a rotation scheme used by Veeam to manage backup copies. GFS allows for multiple levels of retention and can be customized according to your needs.

Calculating Storage Requirements

To calculate the required disk space, you'll need to consider several factors:

1. Number of Restore Points (RP): As mentioned earlier, this is the number of full backups created according to the retention policy.

2. Average VM Disk Changes: This refers to the average amount of data changed between cycles in percent.

3. Total VM Size: This is the actual used size of your virtual machines, not provisioned space.

4. Compression/Dedupe Ratio: This depends on various factors such as compression and dedupe efficiency.

Using these variables, you can calculate the required disk space using the following formula:

Disk Space Required = (RP x Total VM Size) + (Average VM Disk Changes x Total VM Size)

For example, if you have 15 restore points, a total VM size of 7.5 TB, and an average VM disk change rate of 11%, your calculation would be:

Disk Space Required = (15 x 7.5 TB) + (0.11 x 7.5 TB) = 112.5 TB

Calculating Full Backups for Backup Copy Jobs

In Veeam 7, the new backup copy job feature allows you to use GFS-rotation, which creates full backups according to the retention policy. To calculate the number of full backups created in a given situation:

1. Determine your retention period (e.g., 12 months).

2. Calculate the total number of restore points (RP) according to the retention policy.

3. Multiply the RP by the average VM disk changes between cycles in percent.

For example, if you have a 12-month retention period and an average VM disk change rate of 11%, your calculation would be:

Number of Full Backups = RP x Average VM Disk Changes

= 15 (RP) x 0.11 (average VM disk changes)

= 1.65 full backups

In this scenario, you can expect to have approximately 2 full backups created in the first year, with the number decreasing as the retention period increases.

Calculating Veeam backup size requirements can be complex and requires careful consideration of various factors. By using the formula provided above and taking into account your specific configuration, you'll be better equipped to estimate your storage needs. Remember to consider variables such as restore points, average VM disk changes, total VM size, and compression/dedupe ratio when calculating your required disk space.

We hope this article has provided valuable insights into Veeam backup size calculation and will help you plan your storage requirements more effectively.

Veeam backup size calculator