To determine how much backup storage you need for your server, you first need to determine how long you want to retain (keep) older versions of your files.

Example.  The size of the files you want to retain for backups is 25GB.  You would like to retain TWO (2) Weeks of older versions of the files.  To accomplish this, you would need 50GB of backup storage.

Also, keep in mind that at the end of the TWO (2) week retention, the oldest copy is deleted BEFORE the Next backup is started.  Example.  Your retention period starts on January 1.  January 1-7 is kept (25GB), January 8th the second retention period starts.  January 8-14th is kept (Another 25GB).  When the backup job starts on January 15th, the backups for January 1-7 are deleted during the backup run.  When the job ends on January 15th, you can restore from the period of January 8th - 15th.  A total of 50GB.

As you see, the TWO (2) weeks retention is not a full two weeks once the backup job runs.  If you need TWO (2) weeks retention at ANY time, then you would actually need to purchase a THREE (3) week retention period.  75GB if using the numbers in the example above.

Contact a SERVER sales representative if you would like to discuss your backup needs.  We are happy to help accomodate any backup scenarios you have.