Sequential write management in accordance with the present description permits impermissible write retries to be processed by a hard drive such as a Shingled Magnetic Recording (SMR) hard dive. In one embodiment, logic returns a successful write indication in response to a received retry write request operation without writing data to the SMR hard drive if the data of the received retry write operation has already been successfully written to the same location requested by the received retry write request operation. Conversely, a failure notice is returned if the data of the received retry write request operation has not been previously successfully written to the same location requested by the received retry write request operation. Other features and aspects may be realized, depending upon the particular application.

According to one embodiment, a magnetic disk device includes a disk including a first region and a second region different from the first region, a head that writes data on the disk and reads data from the disk, an actuator that positions the head on the disk, and a controller which positions the head by driving the actuator and writes data in the first region and the second region with the head, a skew angle of the head with respect to a circumferential direction of the disk varying within a first angle in the first region, and varying, in the second region, from a second angle larger than the first angle to a third angle larger than the first angle and the second angle.

Methods and systems that reduce off-track write retry operations in shingled magnetic recording systems. In one implementation, the method includes writing data to an initial track, determining which side of the initial track is a shingled side, calculating a percentage of position error signal (PES) at a shingled side end of the initial track (PES1) when an off-track write operation occurs, determining whether the PES1 meets a first pre-determined threshold, continue writing data to a second track responsive to determining the PES1 is below a first pre-determined threshold, calculating a percentage of PES at a shingled side end of the second track (PES2), determining whether a combined value of PES1 and PES2 is above a second predetermined threshold to determine a probability value of the initial track being erased, and continue writing to a third track if the combined value is below the second predetermined threshold.

Methods and systems that reduce off-track write retry operations in shingled magnetic recording systems. In one implementation, the method includes writing data to an initial track, determining which side of the initial track is a shingled side, calculating a percentage of position error signal (PES) at a shingled side end of the initial track (PES1) when an off-track write operation occurs, determining whether the PES1 meets a first pre-determined threshold, continue writing data to a second track responsive to determining the PES1 is below a first pre-determined threshold, calculating a percentage of PES at a shingled side end of the second track (PES2), determining whether a combined value of PES1 and PES2 is above a second predetermined threshold to determine a probability value of the initial track being erased, and continue writing to a third track if the combined value is below the second predetermined threshold.

The disclosed technology provides a system and method that improves interlaced magnetic recording (IMR) data throughput in vibration in storage systems. In one implementation, a method includes determining whether there are write retry operations in the IMR storage device, determining whether bottom track caching space is available responsive to determining whether there are write retry operations in the IMR storage device, performing a vibration detection scheme to identify vibration events responsive to determining whether bottom track caching space is available, determining if a number of vibration events is above a predetermined threshold, and writing data to available bottom track caching space responsive to determining if the number of vibration events is above a predetermined threshold.

A method and system for a controlling a head element of a tape drive is disclosed. Y-position values based on servo bands are identified. Control adjustments for the head element are determined based on the Y-position values and the direction of the current wrap.

Embodiments of the application provide a polar coding method for communicating information in a wireless network. Information bits are encoded using a polar code process to obtain a polar-coded bit sequence. A rate matched bit sequence is output based on the polar-coded bit sequence. The rate matched bit sequence includes a quantity M of bits from the polar-coded bit sequence, and the M bits from the polar-coded bit sequence correspond to M channel indexes in a channel index sequence S. The channel index sequence S is obtained based on a puncturing/shortening proportion P and a prestored channel index sequence S. Channel indexes in the prestored channel index sequence S are sorted by channel reliability or channel capacity, and a sorting order of the M channel indexes in the channel index sequence S is the same as a sorting order of the channel indexes in the prestored channel index sequence S.

A method and system of fault detection for an alert generation system. In the audio alert generation system, a stored digital alert audio file is selected to be processed to generate an analog audio signal to drive a speaker. An alert fault detection system obtaining a signal from the audio alert generation system, converts the obtained signal to a digitally-formatted obtained audio signal, detects a fault in the audio alert generation system by comparing the digitally-formatted obtained audio signal with the stored digital alert audio file, and triggers a fault indicator.

A method and system of fault detection for an alert generation system. In the audio alert generation system, a stored digital alert audio file is selected to be processed to generate an analog audio signal to drive a speaker. An alert fault detection system obtaining a signal from the audio alert generation system, converts the obtained signal to a digitally-formatted obtained audio signal, detects a fault in the audio alert generation system by comparing the digitally-formatted obtained audio signal with the stored digital alert audio file, and triggers a fault indicator.

Technologies are provided for partially updating shingled magnetic recording (SMR) zones in SMR storage devices. An SMR storage device can receive and process a command to update a write pointer for an SMR zone to point to an arbitrary write position within the SMR zone. A partial SMR zone update command can be received and processed to modify part of the data stored in the SMR zone. A write position within the SMR zone where data to be modified is stored can be identified. Data stored in the SMR zone following the identified write position can be read to a temporary location and modified. A write pointer for the SMR zone can be updated to point to the identified write position. The modified data can then be written to the SMR zone, starting at the write position identified by the write pointer, or to another SMR zone of the storage device.