The Storage server consist out of two elements, a server machine (Dell R630) that handles the network access, the file I/O, user and access rights and connects via fibre channel to an extension box (PowerFault MD36xx series). Between the server and the extension box a redundant pair of fibre channels is setup, with two independent interface cards that distribute the workload (load balancing). The system disk of the servers is configure RAID1 for High Availability.
The hardware is bought for expansion. Currently the disk extension box acquired contains 20 disks, and can easily be extended with additional disks to a total of 60 disks. So the current 83TB can be extended to about 250TB by simply acquiring more disks. When the disk cabinet is filled an additional cabinet could store an additinal 250TB of space without any major change to the hardware configuration. Extending the partition size of the shares is done dynamically, so with the addition of new physical disks you will only see that the total size of free space increases. You do not have to use a different share mapping.
The way the data is stored across the disks is in the form of Pools. This means that data is written in a redundant format across all disks simultaneously increasing write performance while making it resistant to multi disk failure. The system is configured such that it will report disk failures so system managemen can take appropriate actions. Currently, the maintenance contract is for four years, while disk replacement can be performed more or less indefinitely.