Holographic Grid Cloud, a futurable high storage technology for the next   generation astronomical facilities
  In the immediate future holographic technology will be available to store a very large amount of data in HVD (Holographic Versatile Disk) devices. This technology make extensive use of the WORM (Write-Once-Read-Many) paradigm: this means that such devices allow for a simultaneous and parallel reading of millions of volumetric pixels (i.e. voxels). This characteristic will make accessible wherever the acquired data from a telescope (or satellite) in a quite-simultaneous way.   With the support of this new technology the aim of this paper is to identify the guidelines for the implementation of a distributed RAID system, a sort of "storage block" to distribute astronomical data over different geographical sites acting as a single remote device as an effect of a property of distributed computing, the abstraction of resources. The end user will only have to take care on connecting in a opportune and secure mode (using personal certificates) to the remote device and will have access to all (or part) of this potential technology.   A Storage-Block+Services engineered on such a platform will allow rapid scalability of resources, creating a "network-distributed cloud" of services for an instrument or a mission. It is recommended the use of a dedicated grid-infrastructure within each single cloud to enhance some critical tasks and to speed-up services working on the redundant, encrypted and compressed scientific data. The power, the accessibility, the degree of parallelism and of redundancy will only depend on the number of distributed storage-blocks: the higher this amount, the greater will be throughput of the IT-system. A storage-block of this kind is a meeting point between two technologies and two antithetical computing paradigms: the Grid-Computing and Cloud-Computing. 
Stefano Gallozzi
astro-ph.IM cs.DC