G11B15/093

Compensation for expansion and contraction across the width of a magnetic tape

A computer data storage system receives a plurality of data units from a host computer. The system stores the data units in a buffer memory. The system generates a plurality of data segments comprising a plurality of subsets of the plurality of data units. The system receives a plurality of dataset information tables (DSITs) corresponding to the plurality of data segments. The system appends the plurality of DSITs to the respectively corresponding plurality of data segments, to create a plurality of datasets stored in the buffer memory. The system determines a number of datasets stored in the buffer memory, exceeds a threshold value. And in response to determining the number of datasets, of the plurality of datasets stored in the buffer memory, exceeds the threshold value, the system stops the appending the plurality of DSITs to the respectively corresponding plurality of data segments.

Rewinder tape drives

A computer-implemented method includes instructing performance of a data operation on a magnetic recording tape using a primary drive, wherein the primary drive rewinds the magnetic recording tape onto a spool at a first tension. The method also includes instructing transfer of the magnetic recording tape to a rewinder drive after performance of the data operation and instructing the rewinder drive to perform a low-tension rewind operation. The low-tension rewind operation includes unspooling the magnetic recording tape from the spool and rewinding the magnetic recording tape onto the spool at a second tension lower than the first tension.

Rewinder tape drives

A computer-implemented method includes instructing performance of a data operation on a magnetic recording tape using a primary drive, wherein the primary drive rewinds the magnetic recording tape onto a spool at a first tension. The method also includes instructing transfer of the magnetic recording tape to a rewinder drive after performance of the data operation and instructing the rewinder drive to perform a low-tension rewind operation. The low-tension rewind operation includes unspooling the magnetic recording tape from the spool and rewinding the magnetic recording tape onto the spool at a second tension lower than the first tension.

Behavioral model for dynamic tension compensation

A tape drive-implemented method, according to one embodiment, includes: detecting a read error, and sending one or more instructions to perform a first re-read attempt on a portion of a magnetic tape corresponding to the read error. In response to determining that the first re-read attempt was unsuccessful, a range of tension settings is selected. A range of lateral offsets is also selected. Moreover, one or more instructions are sent to apply each unique combination of a tension setting from the range of tension settings and a lateral offset from the range of lateral offsets. For each of the unique combinations applied, one or more instructions are sent to perform a second phase re-read attempt on the portion of the magnetic tape corresponding to the read error. Furthermore, a determination is made as to whether the second phase re-read attempt was performed successfully for any of the unique combinations.

Read from a non-trimming portion of a data track written to magnetic tape

An example tape drive includes a magnetic tape head, an actuator, and a controller. The magnetic tape head includes a data write element to write a data track including data onto magnetic tape. The data track includes a non-trimming portion and a trimmable portion. The magnetic tape head also includes a data read element to read the data written to the non-trimming portion of the data track to verify the accuracy of the data. The controller positions the magnetic tape head via the actuator to allow (i) the data write element to write the first data track, and (ii) the data read element to read the second portion of the first data track. From the read data, a determination may be made as to whether the data was written to the non-trimming portion of the data track with a threshold level of accuracy.

Read from a non-trimming portion of a data track written to magnetic tape

An example tape drive includes a magnetic tape head, an actuator, and a controller. The magnetic tape head includes a data write element to write a data track including data onto magnetic tape. The data track includes a non-trimming portion and a trimmable portion. The magnetic tape head also includes a data read element to read the data written to the non-trimming portion of the data track to verify the accuracy of the data. The controller positions the magnetic tape head via the actuator to allow (i) the data write element to write the first data track, and (ii) the data read element to read the second portion of the first data track. From the read data, a determination may be made as to whether the data was written to the non-trimming portion of the data track with a threshold level of accuracy.

READ FROM A NON-TRIMMING PORTION OF A DATA TRACK WRITTEN TO MAGNETIC TAPE

An example tape drive includes a magnetic tape head, an actuator, and a controller. The magnetic tape head includes a data write element to write a data track including data onto magnetic tape. The data track includes a non-trimming portion and a trimmable portion. The magnetic tape head also includes a data read element to read the data written to the non-trimming portion of the data track to verify the accuracy of the data. The controller positions the magnetic tape head via the actuator to allow (i) the data write element to write the first data track, and (ii) the data read element to read the second portion of the first data track. From the read data, a determination may be made as to whether the data was written to the non-trimming portion of the data track with a threshold level of accuracy.

READ FROM A NON-TRIMMING PORTION OF A DATA TRACK WRITTEN TO MAGNETIC TAPE

An example tape drive includes a magnetic tape head, an actuator, and a controller. The magnetic tape head includes a data write element to write a data track including data onto magnetic tape. The data track includes a non-trimming portion and a trimmable portion. The magnetic tape head also includes a data read element to read the data written to the non-trimming portion of the data track to verify the accuracy of the data. The controller positions the magnetic tape head via the actuator to allow (i) the data write element to write the first data track, and (ii) the data read element to read the second portion of the first data track. From the read data, a determination may be made as to whether the data was written to the non-trimming portion of the data track with a threshold level of accuracy.

Read from a non-trimming portion of a data track written to magnetic tape

An example tape drive includes a magnetic tape head, an actuator, and a controller. The magnetic tape head includes a data write element to write a data track including data onto magnetic tape. The data track includes a non-trimming portion and a trimmable portion. The magnetic tape head also includes a data read element to read the data written to the non-trimming portion of the data track to verify the accuracy of the data. The controller positions the magnetic tape head via the actuator to allow (i) the data write element to write the first data track, and (ii) the data read element to read the second portion of the first data track. From the read data, a determination may be made as to whether the data was written to the non-trimming portion of the data track with a threshold level of accuracy.

Read from a non-trimming portion of a data track written to magnetic tape

An example tape drive includes a magnetic tape head, an actuator, and a controller. The magnetic tape head includes a data write element to write a data track including data onto magnetic tape. The data track includes a non-trimming portion and a trimmable portion. The magnetic tape head also includes a data read element to read the data written to the non-trimming portion of the data track to verify the accuracy of the data. The controller positions the magnetic tape head via the actuator to allow (i) the data write element to write the first data track, and (ii) the data read element to read the second portion of the first data track. From the read data, a determination may be made as to whether the data was written to the non-trimming portion of the data track with a threshold level of accuracy.