There are guidelines you can follow to estimate the size of SnapVault secondary storage system volumes for growth over one year, depending on how often you back up data.
The following is an example of how to estimate the daily backup:
Assume a starting baseline transfer of 1 GB and 100 percent growth of new data for the year (1 GB). The changed size due to daily growth if changes are made every weeknight is as follows:
For example, size due to daily growth = (250 x .03) - 1 GB = 7.5 GB - 1 GB = 6.5 GB of change
Therefore, for 1 GB of source data, you need 1 GB baseline + 1 GB new data + 6.5 GB of changed data = 8.5 GB secondary system volume. In other words, you must be able to scale the secondary system volume to about 8 times the current data set size within one year.