The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder, in which an edge portion Ra which is an arithmetic average roughness Ra measured at an edge portion of a surface of the magnetic layer is 1.50 nm or less, a central portion Ra which is an arithmetic average roughness Ra measured at a central portion of the surface of the magnetic layer is 0.30 nm to 1.30 nm, and a Ra ratio (central portion Ra/edge portion Ra) is 0.75 to 0.95.

The magnetic tape cartridge includes a magnetic tape that is accommodated in the magnetic tape cartridge while being wound around a reel hub. The magnetic tape has a non-magnetic support and a magnetic layer including ferromagnetic powder, and includes one or more components selected from the group consisting of a fatty acid and a fatty acid amide in a portion on the magnetic layer side on the non-magnetic support, and after the magnetic tape cartridge is stored in an environment of an atmosphere temperature of 60° C. and a relative humidity of 80% for 24 hours, 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 at a photoelectron take-off angle of 10 degrees on a surface of the magnetic layer in an inner region during winding of the magnetic tape is 45 at % or more.

The magnetic recording medium includes a non-magnetic support, and a magnetic layer including a ferromagnetic powder. The ferromagnetic powder is a ferromagnetic powder selected from the group consisting of a hexagonal strontium ferrite powder and an ε-iron oxide powder. The standard deviation of a height of the magnetic projection portion on a surface of the magnetic layer is in a range of 0.5 to 2.5 nm.

A signal processing device includes a receiver that receives a plurality of playback signal sequence obtained by digitizing a plurality of reading results by a plurality of A/D converter, the plurality of reading results being obtained by reading data by a plurality of reading elements from a magnetic tape and a plurality of equalizers that perform waveform equalization of the plurality of playback signal sequence. The plurality of equalizers perform the waveform equalization by using a plurality of non-linear filters that have been learned to reduce distortion that occurs non-linearly in the plurality of playback signal sequence according to a condition under an environment in which the data is read from the magnetic tape. The plurality of non-linear filters being optimized to a suitable characteristic for the plurality of reading elements by optimization based on the plurality of reading results.

A method according to one embodiment includes measuring a baseline servo band difference (SBD) from a beginning of a tape (BOT) to an end of the tape (EOT), and storing values of the baseline SBD measurements in a memory. A shorter length of the tape that is less than an entire length of the tape is cycled a plurality of times to acclimate the shorter length of the tape. A post cycling SBD of the shorter length of the tape is determined and an acclimation change amount of the shorter length of the tape that is a difference between the baseline SBD of the shorter length and the post cycling SBD of the shorter length is determined. The method further includes adjusting the baseline SBD values based on the determined acclimation change amount.

A hub includes a hub body around which a magnetic tape is wound, and a noncontact storage medium provided in the hub body, in which the noncontact storage medium stores hub specification information for specifying the hub body, and the hub specification information is associated with hub change characteristic information indicating a change characteristic of the hub body.

Embodiments are disclosed for a method. The method includes migrating a file to a newer tape. The file is previously recalled by a linear tape file system (LTFS) from an older tape. The method also includes updating a stub for the file with metadata describing the newer tape, the older tape, and the file. Further, the method includes recalling the file using a tape selected from a plurality of potential tapes identified by the metadata.

A noncontact communication medium includes a processor, and a memory incorporated in or connected to the processor, and performs noncontact communication with an external communication device. The memory has a storage block where information determined depending on a specification of a magnetic tape cartridge, in which the noncontact communication medium is mounted, is stored, and the storage block has an identifier storage field. The processor is configured to write an identifier given from the external communication device to the noncontact communication medium, in the identifier storage field, and execute locking processing of locking the identifier storage field in response to a specific command given from the external communication device to the noncontact communication medium.

A method, according to one embodiment, includes cycling a shorter length of a tape, that is less than an entire length of the tape, a plurality of times to acclimate the shorter length of the tape. An acclimation change amount of the shorter length of the tape is determined. The acclimation change amount is based on a baseline servo band difference (SBD) measured before the cycling and a post cycling SBD measured after the cycling. The method further includes adjusting SBD values from a beginning of the tape (BOT) to an end of the tape (EOT) based on the determined acclimation change amount. A system according to another embodiment includes a processor, and logic integrated with the processor, executable by the processor, or integrated with and executable by the processor. The logic is configured to cause the processor to perform operations of the foregoing method.

A method for generating calibration data useful for calibrating a plurality of tape cartridges includes the steps of selecting a subset of tape cartridges from the plurality of tape cartridges, the subset of tape cartridges having fewer tape cartridges than the plurality of tape cartridges; calibrating each of the subset of tape cartridges using a plurality of tape drives to generate global calibration data; selecting one of the plurality of tape cartridges that is not included within the subset of tape cartridges; and calibrating the one of the plurality of tape cartridges using the global calibration data generated via the calibrating of each of the subset of tape cartridges.