ACRONIS Backup & Recovery 10 Advanced Server Virtual Edition User Manual page 151

If all the backups have to be kept during the year, the archive will require 28 tapes.
As the GFS backup scheme forces automatic deletion of the outdated backups, on the first Friday of
the second year the tapes keep only the backups displayed in the next figure.
Copyright © Acronis, Inc., 2000-2010 151