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CN-121999811-A - Data reading method and tape drive apparatus

CN121999811ACN 121999811 ACN121999811 ACN 121999811ACN-121999811-A

Abstract

A data reading method and tape drive device are provided, which relate to the storage technology field. The data reading method comprises the steps of obtaining an IO request, wherein the IO request comprises an access address, obtaining the tape motion speed of the IO request in the reading and writing process, compensating the estimated phase of at least one data channel according to the tape motion speed to obtain an interpolation phase, and carrying out interpolation and decoding according to the interpolation phase to obtain original data corresponding to the IO request. Therefore, the situation that the estimated phase obtained according to the parameters of the data channel is disordered in phase estimation under the condition that the motion state of the magnetic tape has larger fluctuation due to interference when the data is read is avoided, the error rate of data decoding after phase interpolation is reduced, and the magnetic tape drive equipment can still read the data normally.

Inventors

  • LIU SHUAIJING
  • WANG CHENG
  • CHEN ZHIXIAN

Assignees

  • 成都华为技术有限公司

Dates

Publication Date
20260508
Application Date
20241031

Claims (13)

  1. 1. A data reading method for use with a tape drive apparatus, said tape drive apparatus comprising at least one data channel for transmitting data read from a tape, said method comprising: Acquiring an IO request, wherein the IO request comprises an access address; Acquiring the tape motion speed of the IO request in the read-write process; Compensating the estimated phase of the at least one data channel according to the tape motion speed to obtain an interpolation phase; And carrying out interpolation and decoding according to the interpolation phase to obtain the original data corresponding to the IO request.
  2. 2. The method of claim 1, wherein the tape drive apparatus further comprises at least one servo channel and a speed sensor, the speed sensor being configured to measure a speed of movement of the tape, the at least one servo channel being configured to transmit a control signal, the control signal comprising a read-back signal, the speed of movement of the tape being determined by resolving the read-back signal that reads back data from the access address, or the speed sensor being configured to measure the speed during the reading and writing.
  3. 3. The method of claim 2, wherein the obtaining the tape movement speed of the IO request during reading and writing comprises: Determining whether a fluctuation of the moving speed of the magnetic tape is greater than a preset threshold; if not, the tape motion speed is obtained by analyzing a read-back signal for reading back the data of the access address; if yes, the tape moving speed is measured by the speed sensor in the read-write process.
  4. 4. A method according to any one of claims 1-3, wherein compensating the estimated phase of the at least one data channel based on the speed of tape motion to obtain an interpolated phase comprises: Calculating a corrected frequency deviation of the clock of each of the at least one data channel according to the tape movement speed; and compensating the estimated phase of each data channel according to the corrected frequency deviation of each data channel to obtain the interpolation phase of each data channel.
  5. 5. The method of claim 4, wherein calculating a corrected frequency offset of the clock for each of the at least one data channel based on the speed of tape motion comprises: Determining a current frequency deviation of a clock of the magnetic tape according to the magnetic tape moving speed; Determining a timing error for each data channel; And correcting the estimated frequency deviation of each data channel according to the current frequency deviation and the timing error of each data channel to obtain the corrected frequency deviation of each data channel.
  6. 6. The method of claim 5, wherein compensating the estimated phase of each data channel based on the corrected frequency offset of each data channel to obtain the interpolated phase of each data channel comprises: And calculating the phase of each data channel according to the corrected frequency deviation of each data channel and the timing error to obtain the interpolation phase of each data channel.
  7. 7. The method of claim 4, wherein the at least one data channel comprises n data channels, n being an integer greater than 1, and wherein calculating the corrected frequency offset of the clock for each of the at least one data channels based on the speed of tape motion comprises: Determining a current frequency deviation of a clock of the magnetic tape according to the magnetic tape moving speed; for an ith data channel in the n data channels, determining an estimated timing error, an estimated frequency deviation and an estimated phase of the ith data channel, wherein i is an integer less than or equal to n; Determining the weight of the ith data channel; the estimated timing errors of the n data channels are weighted and summed according to the weights of the n data channels, and the timing error of the ith data channel is obtained; And correcting the estimated frequency deviation of the ith data channel according to the current frequency deviation and the timing error of the ith data channel to obtain the corrected frequency deviation of the ith data channel.
  8. 8. The method of claim 3, wherein the at least one servo channel comprises m servo channels, the at least one data channel comprises n data channels, the tape drive apparatus comprises n heads, m, n being an integer greater than 1, the control signal further comprises a head signal, the compensating the estimated phase of each data channel based on the corrected frequency offset of each data channel to obtain the interpolated phase of each data channel comprises: determining tilt angles of the n heads from the head signals in the m servo channels; Determining phase differences among the n data channels according to the inclination angle and the tape moving speed; and compensating the estimated phase of each data channel according to the corrected frequency deviation of each data channel and the phase difference among the n data channels to obtain the interpolation phase of each data channel.
  9. 9. The method of any of claims 1-8, wherein the tape drive apparatus further comprises an interaction device through which communication between the at least one servo channel and the at least one data channel occurs.
  10. 10. A tape drive apparatus, comprising: A magnetic head; A magnetic tape; A tape drive for driving the magnetic tape; at least one data channel for transmitting data read from said magnetic tape; The computing device is used for acquiring an IO request, wherein the IO request comprises an access address, acquiring the tape motion speed of the IO request in the read-write process, compensating the estimated phase of at least one data channel according to the tape motion speed to obtain an interpolation phase, and carrying out interpolation and decoding according to the interpolation phase to obtain original data corresponding to the IO request.
  11. 11. A computing device, the computing device comprising a processor and a communication interface; the communication interface for obtaining an IO request, the processor and the communication interface for cooperatively performing the method of any one of claims 1-9.
  12. 12. A computer program product containing instructions which, when executed by a computing device, cause the computing device to perform the method of any of claims 1-9.
  13. 13. A computer readable storage medium comprising computer program instructions which, when executed by a computing device, perform the method of any of claims 1-9.

Description

Data reading method and tape drive apparatus Technical Field The present application relates to the field of storage technologies, and in particular, to a data reading method and a tape drive apparatus. Background The tape drive apparatus simultaneously reads and writes data recorded on the tape over a plurality of parallel tracks by a set of head arrays, and the speed of motion of the tape fluctuates within a certain range during the read and write processes, and the actual width of each bit of data on the tape varies during the write or read back process assuming the sample rate of the analog-to-digital converter (analog to digital converter, ADC) is unchanged. To avoid losing data information during sampling, the sampling rate of the ADC typically takes a value slightly greater than the symbol rate (i.e., baud rate), such as 1.05 times or 1.25 times the sampling rate. Therefore, when the tape drive device executes data read-back, the original data symbol rate needs to be restored by adopting a phase estimation and interpolation mode, so that the data decoding order is ensured. However, the magnetic tape is a soft magnetic material, and has a large variation amplitude of the moving speed during the reading and writing of the magnetic tape, and has more interference during the data read-back process of the magnetic tape drive device. The phase estimation and interpolation are sensitive to interference, and cannot be performed stably under the condition of interference, so that the phenomenon of phase estimation disorder is easy to occur due to the large change amplitude of the motion speed of the magnetic tape, and the magnetic tape equipment cannot read data normally. Disclosure of Invention The application provides a data reading method and tape drive equipment, which solve the problem that the tape drive equipment cannot read data normally caused by large variation amplitude of the movement speed of a tape. The application adopts the following technical scheme: In a first aspect, the present application provides a data reading method applied to a tape drive apparatus. The tape drive apparatus includes at least one data channel for transmitting data read from the tape. The data reading method comprises the steps of obtaining an IO request, wherein the IO request comprises an access address, obtaining the tape motion speed of the IO request in the reading and writing process, compensating the estimated phase of at least one data channel according to the tape motion speed to obtain an interpolation phase, and carrying out interpolation and decoding according to the interpolation phase to obtain original data corresponding to the IO request. Based on the data reading method, the motion speed of the magnetic tape is used as priori information of the data channel, and the estimated phase of the data channel is compensated to obtain the interpolation phase, so that the calculation accuracy of the interpolation phase is improved. Therefore, when data is read from the magnetic tape, the situation that the estimated phase obtained according to the parameters of the data channel is disordered when the motion state of the magnetic tape has large fluctuation due to interference is avoided, the error rate of data decoding after phase interpolation is reduced, and the magnetic tape equipment can still read the data normally. With reference to the method provided in the first aspect, as a possible implementation manner, the tape drive apparatus further includes at least one servo channel and a speed sensor, where the speed sensor is used to measure a moving speed of the tape, and the at least one servo channel is used to transmit a control signal, where the control signal includes a read-back signal. The tape moving speed is obtained by analyzing a read-back signal for reading back the data of the access address or is obtained by measuring the speed sensor in the read-write process. The method provided by the first aspect is combined as a possible implementation manner, and the method for obtaining the tape moving speed of the IO request in the read-write process comprises the steps of determining whether the fluctuation of the tape moving speed is larger than a preset threshold value, if not, obtaining the tape moving speed by analyzing a read-back signal for reading back the data of the access address, and if so, obtaining the tape moving speed by measuring the tape moving speed in the read-write process by a speed sensor. Based on the above implementation, a more reliable one of the read-back signal and the speed sensor measurement is selected as the tape movement speed based on the tape movement speed fluctuation. When the fluctuation of the moving speed of the magnetic tape is small, that is, the moving state is stable, the estimated phase of the subsequent data channel is compensated by using the analysis result of the read-back signal, and when the fluctuation of the moving speed of the magnetic tape is large, t