AltaVault AVA400 and AVA800 is comprised of a single 'head unit' and one or more shelves. These raidgroups are independent RAID 6 logical disks that are used together with round-robin loading to form ...AltaVault AVA400 and AVA800 is comprised of a single 'head unit' and one or more shelves. These raidgroups are independent RAID 6 logical disks that are used together with round-robin loading to form the local cache. One of the raidgroups has extra partitions to hold the AVA operating system and the device will not be able to boot unless it is present. If multiple systems are shipped together, the installer can identify what shelves belong to each AVA.