Defining Backup Repository Size

Prior to defining your backup repository size, please get acquainted with NAKIVO Backup & Replication System Requirements.

Making the right decision on the backup repository size will ensure that you avoid performing operations like extending or resizing a backup repository or moving the backup repository to a new location.

The following parameters should be taken into account while defining the size of your backup data:

  • Number of machines to be backed up.

  • Mean size of a machine.

  • Daily data change. An empirical value that characterizes the volatility of your data.

  • Data reduction ratio. This includes compression and deduplication components. When using deduplication appliances, contact the vendor documentation for sizing recommendations.

  • Retention policy. Specifically, the maximum retention period in days that you use for your data can be used to define your backup repository size.

It is possible to roughly define the size of your full backup, FB, based on the following expression:


where ODS is the original data size, and DCR is the data reduction ratio.

The size of your daily increment, DI, can be defined as:

DI = FB * DDC,

where FB is the size of your full backup, and DDC is the daily data change – an empirical value that characterizes the volatility of your data.

Finally, the total size of the backup repository, RS, can be defined as:

RS = FB + DI * MRC,

where MRC is the maximum retention period in days that you can use for your data.

When the maximum retention period is 30 days, the daily data change is 3%, and the data reduction ratio is 50%, the following free storage is recommended to be available depending on the size of your original data:

  • Typical storage scenario – suitable for small infrastructure consisting of about 50 machines with about 500 GB disk each. This will require 23.75 TB of free storage.

  • Medium storage – suitable for an infrastructure consisting of about 500 similar machines. This will require 237.5 TB of free storage.

  • Large storage – your infrastructure consists of about 5,000 machines which will require 2,375 TB.

You must also add extra space for future data growth, additional backups, relocation and recovery of machines.