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At least 181 records · Page 10

Low-Latency Ultra-High Capacity Holographic Data Storage Archive Library

Akonia has successfully completed all of its milestones and tasks for Phase 1. The results of these tasks met or exceeded our expectations and we are highly encouraged that every milestone in Phase 2 will be achievable moving forward. One of the highest risk tasks of Phase 1, achieving 1 Tbit/in2 bit densities, was accomplished by August and exceeded our Phase 1 goal by 35%. We achieved world record bit densities of 1.35Terabit/in2 and set our expectations of achieving our goal of 2 Terabits/in2 in Phase 2 quite high with a strong potential for exceeding this bit density as well. Additionally, Phase 1 allowed us to develop some very promising design concepts that would allow holographic storage to be retro-fit into existing LTO library systems with minimum impact on the library designs. These CAD designs are outlined in Section 1 including a new concept of a holographic media card (HMC) that can be stacked in a group of 5 and placed in a magazine that is exactly size compatible with an LTO tape, but will be able to hold at least 10 Terabytes of uncompressed data compared to todays LTO6 format that holds 2.5 Terabytes.

Anderson, Ken↗

Problems in the long-term storage of data obtained from scientific space experiments

It is shown that long-term data storage systems can be achieved when the system which organizes and conducts the scientific space experiments is equipped with a specialized subsystem: the information filing system. Its main functions are described along with the necessity of stage-by-stage development and compatibility with the data processing systems. The requirements for long-term data storage media are discussed.

Zlotin, G. N.↗

Petascale Data Storage Institute (Final Report)

pNFS is an extension to NFSv4 that helps clients overcome NFS scalability and performance barriers. Like NFS, pNFS is a client/server protocol implemented with secure and reliable remote procedure calls. pNFS departs from conventional NFS by allowing clients to access storage directly and in parallel. This helps overcome server bottlenecks inherent to NAS access methods. Making pNFS available to petascale researchers required coordinated progress in several dimensions, a confluence of multiple processes that took nearly ten years. The protocol had to be specified and published by the IETF. Nascent implementations had to track changes in the draft specification, changes in the Linux kernel, and interoperate with one another. The process by which modifications are accepted into the Linux kernel by maintainers and developers (and ultimately by Linus Torvalds himself) itself required consensus and compromise. Finally, pNFS support needed to be provided by the major Linux distributors (Red Hat, SUSE, etc.) and storage vendors (Netapp, EMC, IBM, Microsoft, etc.) on both the engineering and product sides. The specification requirement was met in December 2008, when the IETF approved the NFSv4.1 specification, which incorporates pNFS and pNFS file layouts, as a Proposed Standard as well as the (separate) specifications of pNFS object and block layouts. Throughout the PDSI project, CITI was the key contributor to the Linux-based, open source implementation of NFSv4.1 and pNFS. Considerable effort was devoted to the process of refining the IETF specification, which underwent dozens of preliminary drafts, rebasing implementations to the latest Linux kernel, which itself changed quarterly, and to testing interoperability with other developers. At last, the Linux pNFS implementation was incorporated into the Linux mainline kernel, although this was achieved after the PDSI project ended.

97 MATHEMATICS AND COMPUTING↗

Circuitry selectively limits data storage in general purpose computer

Circuitry limits storage in the memory of a stored program general purpose digital computer by permitting storage or writing to certain, specified areas of memory. The limit register used in the computer is easily set under program control, and the memory block size and position is readily changed to suit each specific program.

Slopper, D. K.↗

Crystal gazing. Part 2: Implications of advanced in digital data storage technology

During the next 5-10 years it is likely that the bit density available in digital mass storage systems (magnetic tapes, optical and magnetic disks) will be increased to such an extent that it will greatly exceed that of the conventional photographic emulsions like IIIaJ which are used in astronomy. These developments imply that it will soon be advantageous for astronomers to use microdensitometers to completely digitize all photographic plates soon after they are developed. Distribution of digital copies of sky surveys and the contents of plate vaults will probably become feasible within ten years. Copies of other astronomical archieves (e.g., Space Telescope) could also be distributed with the same techniques. The implications for designers of future microdensitometers are: (1) there will be a continuing need for precision digitization of large-format photographic imagery, and (2) that the need for real-time analysis of the output of microdensitometers will decrease.

Wells, D. C.↗

Holographic data storage crystals for the LDEF

Crystals of lithium niobate were passively exposed to the space environment of the Long Duration Exposure Facility (LDEF). Three of the four crystals contained volume holograms. Although the crystals suffered the surface damage characteristic of that suffered by other components on the Georgia Tech tray, the crystals remained suitable for the formation of volume holograms.

Callen, W. Russell↗

Data storage: Retrospective and prospective

We study history to learn from its lessons so we don't repeat the mistakes. Ironically, however, sometimes it seems that the lessons we learn from history is how to repeat the mistakes more precisely. A brief discussion about the history of magnetic recording is presented, and the lessons of the past are used to look into the future.

Speliotis, Dennis E.↗

Optical Experiments With Manganese Doped Yttrium Orthoaluminate, a Potential Material for Holographic Recording and Data Storage

The YAlO3 host crystal has a distorted perovskite structure that belongs to the orthorhombic centrosymmetric Pbnm space group. The cationic sites in the structure available for Mn substitution are the relatively large strongly distorted YO12 polyhedral (Y3+ ionic radius R(sub Y) = 1.02 A) and the smaller nearly ideal AlO6 octahedra R(sub Al) = 0.53 A). Manganese may enter YAlO3 in the form of Mn2+ ions (R(sub Mn)= 0.96 A), substituting most likely Y3+ ions, and Mn3+ ions (R(sub Mn) = 0.65 A) or Mn4+ ions (R(sub Mn) = 0.53 A) substituting Al3+ ions. The latter substitution is most probable because of dimensional parameters. Point defects, which are common in YAl03, may provide the charge compensation required for substitution.

Warren, Matthew E.↗