ECC is used to for controlling errors in blocks of data by including a measure of redundancy within the data for recovering one or more unreadable portions of the data. A codeword includes at least a message and one or more additional ECC blocks. In the event of an unreadable sector, the ECC is decoded and used to recover the erroneous or missing portion(s) of the message. With disc access parallelism, ECCs can now be distributed across data storage surfaces and/or multiple storage platters. Distribution of ECCs increases the likelihood of recovering data from a head failure or from burst errors on a data storage surface and adds the option to decode parity after only 1/n revolutions.

According to one embodiment, a magnetic disk includes a disk, first and second heads which write data to the disk and read data from the disk, a first actuator includes the first head, a second actuator includes the second head, first and second controllers which control the first head, the second head, the first actuator and the second actuator, an auxiliary power supply which supplies power when power from a power supply is shut off, and a power supply detection unit which makes power supplied from the auxiliary power supply to the first controller higher than the power supplied from the auxiliary power supply to the second controller when shutoff of power from the power supply is detected.

According to one embodiment, a suspension assembly includes a support plate, a wiring member disposed on the support plate, and a head supported on the support plate through the wiring member. The wiring member includes a distal end portion electrically connected to the head, a connection end portion extending outside the support plate, and a plurality of wirings extending between the distal end portion and the connection end portion. The connection end portion includes an opening with predetermined length and width and thirteen or more connection terminals disposed in the opening and arranged at intervals in a direction of the length. A percentage of an area of the opening occupied by areas of the thirteen or more connection terminals is 40% to 65% inclusive.

A pivot assembly bearing apparatus includes: a shaft extending in an axial direction, a first rolling bearing, a second rolling bearing and a first sleeve bonded to an outer peripheral surface of the first outer ring of the first rolling bearing, a second sleeve bonded to an outer peripheral surface of the second outer ring of the second rolling bearing and a spacer abutting on a lower end surface of the first outer ring and an upper end surface of the second outer ring. A part of the first sleeve protruding downwards in the axial direction from the first outer ring is bonded to the spacer, and a part of the second sleeve protruding upwards in the axial direction from the second outer ring is bonded to the spacer.

In a multi-actuator drive, the effect of moving a first actuator (the so-called “aggressor actuator”) in on a second actuator (the so-called “victim actuator”) is reduced or compensated for. A victim feedforward signal for a particular head of the victim actuator is added to a microactuator control signal of the victim actuator in response to a voice-coil motor (VCM) control signal that is applied to the aggressor actuator. The feedforward signal is configured to compensate for disturbances to the victim microactuator caused by VCM commands provided to the aggressor actuator. The feedforward signal is based on a transfer function that models commands added to the victim microactuator, which is coupled to the particular head of the victim actuator, as a function of the aggressor VCM control signal applied to the aggressor actuator.

In a multi-actuator drive, the effect of moving a first actuator (the so-called “aggressor actuator”) in on a second actuator (the so-called “victim actuator”) is reduced or compensated for. A victim feedforward signal for a particular head of the victim actuator is added to a microactuator control signal of the victim actuator in response to a voice-coil motor (VCM) control signal that is applied to the aggressor actuator. The feedforward signal is configured to compensate for disturbances to the victim microactuator caused by VCM commands provided to the aggressor actuator. The feedforward signal is based on a transfer function that models commands added to the victim microactuator, which is coupled to the particular head of the victim actuator, as a function of the aggressor VCM control signal applied to the aggressor actuator.

According to one embodiment, a suspension assembly includes a support plate, a wiring member disposed on the support plate, and a head supported on the support plate through the wiring member. The wiring member includes a distal end portion electrically connected to the head, a connection end portion extending outside the support plate, and a plurality of wirings extending between the distal end portion and the connection end portion. The connection end portion includes an opening with predetermined length and width and thirteen or more connection terminals disposed in the opening and arranged at intervals in a direction of the length. A percentage of an area of the opening occupied by areas of the thirteen or more connection terminals is 40% to 65% inclusive.

According to one embodiment, a magnetic disk device includes a plurality of disks including a first area to which data is randomly written in normal recording and to which an LBA is added, and a second area to which data is written in shingled recording to write a plurality of tracks overlaid in a radial direction and to which an LBA is added, a plurality of heads, and a controller which writes data to the first area in the normal recording, writes data to the second area in the shingled recording, and changes the first area in accordance with a first recording capacity of a first recording surface in each of the disks, which corresponds to a first head of the heads, when the first head is inhibited from being used.

According to one embodiment, a magnetic disk includes a disk, first and second heads which write data to the disk and read data from the disk, a first actuator includes the first head, a second actuator includes the second head, first and second controllers which control the first head, the second head, the first actuator and the second actuator, an auxiliary power supply which supplies power when power from a power supply is shut off, and a power supply detection unit which makes power supplied from the auxiliary power supply to the first controller higher than the power supplied from the auxiliary power supply to the second controller when shutoff of power from the power supply is detected.

A method of manufacturing a tri-stage assembly is provided. The method includes attaching a first microactuator and a second microactuator to a trace gimbal to a flexure during a PZT on flexure process (POF). The first microactuator is located at a distal end of the flexure and the second microactuator located at a proximal end of the flexure. The method also includes welding the trace gimbal to a baseplate, and a load beam to secure the trace gimbal including the first microactuator and the second microactuator.