The dual 8D hub stack is our entry-level redundant multi-server environment. With this simple and inexpensive configuration. You can access all the Hub server features like RAID50 spanned volumes for aggregate bandwidth and RAID51 server mirroring for data and up-time resiliency. Up to 64TB of raw capacity can be completely redundant, and failure-proof at the drive, controller and server-level. Or, use RAID50 for efficient use of space, and add an inexpensive 128TB nearline array for backup.