Abstract: This invention extends the distance at which a SAS extender can function. The distance is increased a large amount over the traditional 10 meters. As a result timers will not go off before the response can make a trip back. This is accomplished by emulating as a SAS expander, using SAS AIP's (Arbitration In Progress), and using a lookup table to determine which SAS events must be responded to immediately and which ones to be passed on to the remote link.

Abstract: An apparatus, system, and method are disclosed for hard disk drive redundancy. A demarcation module demarks a parity data block in each set of a specified number of data blocks on a hard disk drive. An association module associates a PBA of each un-demarked data block with a LBA. A write module writes the data to the un-demarked data blocks. A parity module calculates parity data for the data written to the un-demarked data blocks and the write module writes the parity data to the parity data block.

Abstract: A method, system and article of manufacture for the storing convolution-encoded data on a redundant array of independent storage devices (RAID) is described. The convolution-encoded data comprises error correction coded data to eliminate the need for parity as used in conventional RAID data storage. The number of storage devices may vary to accommodate expansion of storage capacity and provide on demand storage.

Abstract: A dual-path optical recording medium and an apparatus for accessing such are disclosed. The dual-path optical recording medium includes a substrate, an intermediate recording layer, a holographic recording layer and a dichronic mirror layer. The intermediate recording layer is a rewritable data storage layer with a relatively low storage capacity. The holographic recording layer is a write-once data storage layer with a relatively high storage capacity. The dichronic mirror layer is located between the holographic recording layer and the intermediate recording layer. The apparatus for accessing the dual-path optical recording medium includes a first light module capable of generating a first laser light, and a second light module capable of generating a second laser light.

Abstract: A dual-path optical recording medium and an apparatus for accessing such are disclosed. The dual-path optical recording medium includes a substrate, an intermediate recording layer, a holographic recording layer and a dichronic mirror layer. The intermediate recording layer is a rewritable data storage layer with a relatively low storage capacity. The holographic recording layer is a write-once data storage layer with a relatively high storage capacity. The dichronic mirror layer is located between the holographic recording layer and the intermediate recording layer. The apparatus for accessing the dual-path optical recording medium includes a first light module capable of generating a first laser light, and a second light module capable of generating a second laser light.

Abstract: A velocity calculator performs high-order calculations of servo frame velocities of a storage media, particularly tape and disk. The velocity calculator employs a servo frame indexing module for generating a first-order preceding servo frame velocity signal indicative of a first-order calculation of a preceding servo frame velocity including a first-order preceding servo frame error term based on first-order current servo frame velocity signal indicative of a first-order calculation of a current servo frame velocity including a first-order current servo frame error term. The velocity calculator further employs a velocity estimating module for generating a higher-order current servo frame velocity signal indicative of a second or higher order velocity calculation of the current servo frame velocity including a higher-order current servo frame error term based on the first-order preceding servo frame velocity signal and the first-order current servo frame velocity signal.

Abstract: A Redundant Array of Independent Devices uses convolution encoding to provide redundancy of the striped data written to the devices. No parity is utilized in the convolution encoding process. Trellis decoding is used for both reading the data from the RAID and for rebuilding missing encoded data from one or more failed devices, based on a minimal, and preferably zero, Hamming distance for selecting the connected path through the trellis diagram.

Abstract: A method, system and article of manufacture for the storing convolution-encoded data on a redundant array of independent storage devices (RAID) is described. The convolution-encoded data comprises error correction coded data to eliminate the need for parity as used in conventional RAID data storage. The number of storage devices may vary to accommodate expansion of storage capacity and provide on demand storage.

Abstract: A secure data system employs a storage media and a storage drive. A storage media identification key is embedded in a non-user modifiable area of the storage media and associated with data recorded on the storage media. The storage drive includes a memory having a storage drive identification key embedded therein. In operation, the storage drive allows access to the data recorded on the storage media based on a validation by the storage drive of the storage drive identification key as a function of the storage media identification key.

Abstract: A Redundant Array of Independent Devices uses convolution encoding to provide redundancy of the striped data written to the devices. No parity is utilized in the convolution encoding process. Trellis decoding is used for both reading the data from the RAID and for rebuilding missing encoded data from one or more failed devices, based on a minimal, and preferably zero, Hamming distance for selecting the connected path through the trellis diagram.

Abstract: A system and method for measuring data transmission activity through a port of a switch device interconnecting nodes of a storage area network, the port transmitting data as words of predetermined length, one data word indicating idle port activity. The method includes steps of counting a number of transmitted words received from the port in a first counter device; and, for each word counted, comparing that word with a predetermined word indicating no (idle) port transmission activity. In response to the comparing, a number of matches are counted in a second counter device. In this manner, a ratio of a number of counted matches with a total amount of words counted indicates available bandwidth for transmitting additional data over that link. Preferably, this available bandwidth information is included in a link state record that the switch communicates to other switch devices interconnecting that link.

Abstract: A velocity calculator performs high-order calculations of servo frame velocities of a storage media, particularly tape and disk. The velocity calculator employs a servo frame indexing module for generating a first-order preceding servo frame velocity signal indicative of a first-order calculation of a preceding servo frame velocity including a first-order preceding servo frame error term based on first-order current servo frame velocity signal indicative of a first-order calculation of a current servo frame velocity including a first-order current servo frame error term. The velocity calculator further employs a velocity estimating module for generating a higher-order current servo frame velocity signal indicative of a second or higher order velocity calculation of the current servo frame velocity including a higher-order current servo frame error term based on the first-order preceding servo frame velocity signal and the first-order current servo frame velocity signal.

Abstract: A magnetic storage media has a servo track segment and a timing based servo band recorded on the servo track segment. The timing based servo band includes a modulated timing based servo pattern string representative of magnetic encoded servo position information for facilitating a determination of a servo position error signal. Exemplary forms of the modulation of the timing based servo pattern string includes a pattern interspacing modulation, a magnetic intensity modulation, and a pulse position modulation.

Abstract: A transceiver test module and method for testing an optical transceiver. An optical wrap interconnects the optical transmitter and optical receiver of an optical transceiver. A processor system reads information from an optical transceiver; provides a signal to the optical transceiver to operate the optical transceiver to transmit a signal at the optical transmitter, which is received via the optical wrap; detects diagnostic information from the optical transceiver for errors of the optical transceiver; and determines the rated speed of the optical transceiver from the read information. Operation of the optical transceiver at the rated speed is verified by the diagnostic information.

Abstract: A holographic information recording apparatus is disclosed. The holographic information recording apparatus comprises a laser light source, a beam splitter, and a reflective spatial light modulator. The beam splitter provides a reference beam and a carrier beam, where that reference beam is directed without reflection toward a holographic data storage medium. The carrier beam is reflected off the reflective spatial light modulator to form a data beam comprising an image of information. The reference beam interacts with the data beam to form a hologram comprising the image. That hologram is then encoded in a holographic data storage medium.

Abstract: Improved reliability for multi-layer media is providing by the present invention. A data stream U is received for recording to a multi-layer rotating storage medium, the data stream U comprising a sequence of data bits. Each data bit U(J) is encoded into X representation bits. A first representation bit B(1,J) is recorded onto a first layer of the storage media, the second representation bit B(2,J) is recorded onto a second layer of the storage media, etc. When a request to read the recorded data U from the storage media is subsequently received, a plurality of the X representation bits are read back from the storage media and are decoded into the original data bit U(J). In one embodiment, encoding may be performed with a convolution encoding algorithm and decoding with a PRML decoding algorithm. In another embodiment, Reed Solomon encoding/decoding may be employed.

Abstract: A data storage cartridge comprises data storage media configured to store data for read and/or write access, wherein the data may be arranged in a plurality of partitions; and a plurality of cartridge memories. Each cartridge memory comprises a communication interface and a memory, wherein the information of the memory is formatted to allow association with at least one of the plurality of partitions of the data storage media. Thus, each of the cartridge memories may have a separate user and provide access for that user to a separate partition or subset of partitions.

Abstract: A data storage cartridge comprises data storage media configured to store data for read and/or write access, wherein the data may be arranged in a plurality of partitions; and a plurality of cartridge memories. A control system, for example of a data storage drive, is configured to allocate at least portions of capacity of the data storage media to cartridge memories of the data storage cartridge; and to provide information defining the allocated portions of capacity to the cartridge memories. Each of the cartridge memories may have a separate user and thus provide access for that user to separate partitions.

Abstract: A magnetic storage media includes a magnetic first-pole polarity initialized servo track segment and a magnetic second-pole polarity differential timing based servo pattern recorded on the magnetic first-pole polarity initialized servo track segment The magnetic second-pole polarity differential timing based servo pattern represents magnetic encoded servo position information for facilitating a determination of a servo position error signal exclusive of a plurality of fixed position error timing components and inclusive of a plurality of variable position error timing components.

Abstract: A magnetic storage media includes a magnetic first-pole polarity initialized servo track segment and a magnetic second-pole polarity differential timing based servo pattern recorded on the magnetic first-pole polarity initialized servo track segment. The magnetic second-pole polarity differential timing based servo pattern represents magnetic encoded servo position information for facilitating a determination of a servo position error signal exclusive of noise.