Question About Free Space

Hello,

I am running Backup and Recovery 10, Update 3, on three servers which are all backing up to a NAS device. I am trying to determine how much free space I need on the NAS to backup the three servers, each using a GFS policy.

How does Acronis determine the amount of free space needed for backups? If I look at the task details on one of the servers, under "What to back up," it shows the size of the volumes that I'm backing up, but that number is much greater than the space that is actually being used on those volumes.

Does my free storage space need to be greater than the "What to back up" sizes listed on each of the servers?

Thank you