In one embodiment, a method for writing data to a magnetic recording tape includes writing a plurality of files to a first partition of a magnetic recording tape using a tape drive, and writing an index to a second partition of the magnetic recording tape using the tape drive, the index including information about locations of data of the plurality of files in the first partition of the magnetic recording tape

File index, metadata storage, and file system management for magnetic tape

The magnetic tape includes a magnetic layer having ferromagnetic powder and a binder on a non-magnetic support, in which the magnetic layer includes a timing-based servo pattern, the ferromagnetic powder is ferromagnetic hexagonal ferrite powder having an activation volume equal to or smaller than 1,600 nm 3 , and an edge shape of the timing-based servo pattern specified by a magnetic force microscope observation is a shape in which a difference (l 99.9 −l 0.1 ) between a value l 99.9 of a cumulative frequency function of 99.9% of a position deviation width from an ideal shape in a longitudinal direction of the magnetic tape and a value l 0.1 of the cumulative frequency function of 0.1% thereof is equal to or smaller than 180 nm.

Magnetic tape and magnetic tape device

The magnetic tape device includes a magnetic tape including a magnetic layer, in which an intensity ratio of a peak intensity of a diffraction peak of a (110) plane with respect to a peak intensity of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00, Ra measured regarding a surface of the magnetic layer is equal to or smaller than 2.0 nm, and a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the magnetic layer at a photoelectron take-off angle of 10 degrees is 45 to 65 atom %.

Magnetic tape device and head tracking servo method

Provided is a magnetic tape, which comprises, on a nonmagnetic support, a nonmagnetic layer comprising nonmagnetic powder and binder, and on the nonmagnetic layer, a magnetic layer comprising ferromagnetic powder and binder; wherein at least the magnetic layer comprises one or more components selected from the group consisting of a fatty acid and a fatty acid amide; a quantity of components selected from the group consisting of a fatty acid and a fatty acid amide per unit area of the magnetic tape among components that are extracted from a surface on the magnetic layer side of the magnetic tape is less than or equal to 15.0 mg/m2, and a concentration of carbon, C, that is obtained by X-ray photoelectron spectroscopy conducted at a photoelectron take-off angle of 10 degrees on the surface on the magnetic layer side of the magnetic tape is greater than or equal to 50 atom %.

Magnetic tape and method of manufacturing the same

A multi-tiered filesystem integrates multiple types of storage devices into a contiguous filesystem storage space having regions associated with two or more tiers of storage.

Multi-tiered filesystem

Rolling back data on tape in a file system is provided. A management tape is prepared. The management tape has only index files recorded thereon. The index files contain information about start positions and lengths of corresponding data files recorded on normal tapes. The index files further contain identification information for the normal tapes. A first index file of the management tape is read. The first index file is related to a data file to be rolled back. The first index file is read out from the management tape mounted on a first tape drive. The data file to be rolled back is read out of a first normal tape. The first normal tape is identified based on information in the first index file. The first normal tape is mounted on a second tape drive.

File system for rolling back data on tape

A write/read control method for recording at least one datum on a magnetic tape within a predetermined distance is provided. The method includes sequentially accumulating a plurality of blocks of data of variable length in a buffer divided into fixed length segments and writing the contents of each segment to the tape. If the segment contains at least one block of data, the data is written to the tape as a dataset and if the segment does not contain any data, then a null dataset is written to the tape within the predetermined distance. The predetermined distance may vary depending upon the format of a tape drive embodying the method. In response to a request to read a block of data, reading at least one dataset that includes the requested block of data from the tape to segments in the buffer, and reading the requested block of data for invalidating data transfer of a null dataset in the segment. By invalidating the transfer of a null dataset, blocks of data separated by the null dataset can be reconstructed.

Method of controlling write and read of data for tape recording apparatus

Provided is a tape recorder that has a tape including at least one partition and that controls access to the tape. The tape recorder includes: means for identifying a position of data on the tape; means for sequentially reading necessary data areas in the data; means for sequentially copying the necessary data areas to the beginning of an empty area on the tape; means for creating a continuous front empty area formed of unnecessary data areas and copy source areas of the necessary data areas on the tape; and means for moving a beginning of the partition (BOP) to a position immediately after the front empty area and for updating the position information on the beginning of the partition.

Tape Recorder And Tape Recording That Increases Empty Tape Area Without Loss of Necessary Data

A storage system includes a plurality of tape drives connected to a host, and a buffer configured to temporarily hold data read from the drives. A mechanism loads a plurality of media on which a file has been written to the plurality of drives so as to mount the plurality of media in the plurality of drives and divides the file into a plurality of data portions in an order. The mechanism determines a medium that takes the shortest time to move from a current position of a read head of a corresponding drive to a beginning position of the file and one or more media from which following data portions of the beginning data portion are to be read. The mechanism executes reading of the following data portions from the next media and temporarily holding of the read following data portions in the buffer of the storage system while reading the beginning data portion of the file from the first medium to the host.

Method for reading file using plurality of tape media

Mechanisms for writing a file on a tape medium in a manner that enables high-speed reading are provided. A predetermined format is applied to the medium that divides the medium into a first region of a predetermined length in a longitudinal direction from a region of the medium, and a second region that extends from an end of the first region to a terminal region of the medium in a longitudinal direction and that has a predetermined width with respect to a width of the medium in a transverse direction. Writing a top data portion of a predetermined data amount of the data of the file in the first region and writing data of the file in the second region are performed.

Terue Watanabe

Papers

File system for rolling back data on tape

Method of controlling write and read of data for tape recording apparatus

Tape Recorder And Tape Recording That Increases Empty Tape Area Without Loss of Necessary Data

Method for reading file using plurality of tape media

Method for Writing File on Tape Medium that can be Read at High Speed