Disk device

Abstract

The embodiment provides a magnetic disk device capable of improving data reliability. The magnetic disk device involved in the embodiment comprises: a first disk having a first user data area and a first system area; a second disk having a second user data area and a second system area; a first head that writes data to the first disk and reads data from the first disk; a second head that writes data to the second disk and reads data from the second disk; a first actuator having a first head; a second actuator having a second head; a first controller that controls the first disk, the first head, and the first actuator; and a second controller that controls the second disk, the second head, and the second actuator, and the first controller records first information associated with the first head and the first disk in the second system area.

Description

[0001] This application claims the priority of Japanese Patent Application No. 2020-153963 (filing date: September 14, 2020) as a basic application, and the present application incorporates the entire contents of the basic application by reference. Technical Field

[0002] An embodiment of the present invention relates to a magnetic disk device. Background Art

[0003] In a magnetic disk device, when data is written, side erase (side erase) in which data is erased may occur due to the influence of leakage flux from the head (Adjacent Track Interference: ATI). ATI varies depending on, for example, the characteristics of the head, the track per inch (TPI) setting value, and the write current setting value. In order to prevent side erase, the magnetic disk device has the following function (refresh function): when the degree or number of times (hereinafter sometimes referred to as ATI number) corresponding to the number of times data is written to the peripheral tracks of the predetermined track reaches a predetermined number, the data of the predetermined track is rewritten. The magnetic disk device manages the ATI number by recording it as a table in a predetermined recording area.

[0004] In addition, in recent years, along with the increase in the recording capacity of the magnetic disk device, the number of magnetic disks has also increased. In order to cope with the increase in magnetic disks, a so-called split actuator magnetic disk device having multiple, for example, two actuators has been proposed. The split actuator magnetic disk device has multiple controllers in order to independently control the multiple actuators. The split actuator magnetic disk device manages the ATI times by actuator as a table recorded in a predetermined recording area. Summary of the invention

[0005] An embodiment of the present invention provides a magnetic disk device capable of improving data reliability.

[0006] The magnetic disk device involved in this embodiment comprises: a first disk, which has a first user data area for writing user data and a first system area different from the first user data area; a second disk, which has a second user data area for writing user data and a second system area different from the second user data area; a first head, which writes data to the first disk and reads data from the first disk; a second head, which writes data to the second disk and reads data from the second disk; a first actuator, which has the first head; a second actuator, which has the second head; a first controller, which controls the first disk, the first head and the first actuator; and a second controller, which controls the second disk, the second head and the second actuator, and the first controller records first information associated with the first head and the first disk in the second system area. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a block diagram showing the structure of a magnetic disk device according to an embodiment.

[0008] Figure 2 It is a schematic diagram showing a configuration example of a system controller according to an embodiment.

[0009] Figure 3 This is a schematic diagram showing an example of the number of ATIs added to the peripheral area according to the number of times writing is performed on a predetermined track 0.

[0010] Figure 4 This is a diagram showing an example of an internal log table.

[0011] Figure 5 This is a schematic diagram showing an example of a method for managing an internal log table according to an embodiment.

[0012] Figure 6 This is a schematic diagram showing an example of a method for managing an internal log table according to an embodiment.

[0013] Figure 7 This is a flowchart showing an example of a method for managing an internal log table according to an embodiment.

[0014] Figure 8 This is a schematic diagram showing a configuration example of a system controller according to Modification 1.

[0015] Fig. 9 This is a schematic diagram showing an example of a method for managing the internal log table according to Modification 1.

[0016] Fig.10 This is a schematic diagram showing an example of a method for managing the internal log table according to Modification 1.

[0017] Fig.11 This is a schematic diagram showing an example of a method for managing the internal log table according to Modification 1. DETAILED DESCRIPTION

[0018] Hereinafter, the embodiments will be described with reference to the drawings. Note that the drawings are examples and do not limit the scope of the invention.

[0019] (Implementation Method)

[0020] Figure 1 It is a block diagram showing the structure of the magnetic disk device 1 according to the embodiment.

[0021] The magnetic disk device 1 includes a head disk assembly (HDA) described later, a driver IC 20, a head amplifier integrated circuit (hereinafter referred to as a head amplifier IC or a pre-amplifier) ​​30, a volatile memory 70, a buffer memory (cache) 50, a non-volatile memory 80, and a system controller 130 as an integrated circuit of one chip. In addition, the magnetic disk device 1 is connected to a host system (hereinafter referred to as a host) 100. The magnetic disk device 1 is a split-actuator magnetic disk device that can independently drive a plurality of, for example, two, actuators 16 described later. In addition, the magnetic disk device 1 may have more than two actuators 16.

[0022] The HDA has a magnetic disk (hereinafter referred to as disk) 10, a spindle motor (hereinafter referred to as SPM) 12, an arm 13 on which a head 15 is mounted, and a voice coil motor (hereinafter referred to as VCM) 14. The disk 10 is mounted on the spindle motor 12 and rotated by the drive of the spindle motor 12. The disk 10 includes, for example, disks 10A and 10B. In addition, the disk 10 may also include three or more disks. In addition, the disks 10A and 10B may each include two or more disks. The arm 13 includes, for example, arms 13A and 13B. In addition, the arm 13 may also include three or more arms. The arms 13A and 13B may each include two or more arms. The VCM 14 includes, for example, VCM 14A and 14B. In addition, the VCM 14 may also include three or more VCMs. The head 15 includes, for example, heads 15A and 15B. In addition, the head 15 may also include three or more heads. In addition, the heads 15A and 15B may each include two or more heads. For example, the head 15A is mounted on the arm 13A. In addition, for example, the head 15B is mounted on the arm 13B.

[0023] The actuator 16 includes actuators 16A and 16B. In addition, the actuator 16 may include more than three actuators. The actuators 16A and 16B are mounted on a common pivot and can rotate independently around the pivot. The actuator 16A is composed of an arm 13A and a VCM 14A. In addition, the actuator 16A may also include a head 15A, a driver IC 20, and a head amplifier IC 30. The actuator 16A controls the head 15A mounted on the arm 13A to move to a predetermined position of the disk 10A by the drive of the VCM 14A. The actuator 16B includes an arm 13B and a VCM 14B. In addition, the actuator 16B may also include a head 15B, a driver IC 20, and a head amplifier IC 30. The actuator 16B controls the head 15B mounted on the arm 13B to move to a predetermined position of the disk 10B by the drive of the VCM 14B.

[0024] The disk 10 allocates a user data area that can be used by the user and a system area for writing information required for system management to the area where data can be written. For example, the disk 10A is allocated with a user data area 10A1 and a system area 10A2. The disk 10B is allocated with a user data area 10B1 and a system area 10B2. Hereinafter, the direction perpendicular to the radial direction of the disk 10 is referred to as the circumferential direction.

[0025] The head 15 has a slider as a main body and includes a write head and a read head mounted on the slider. The write head writes data to the disk 10. The read head reads the data written on the disk 10. For example, the head 15A includes a write head 15WA that writes data to the disk 10A and a read head 15RA that reads the data written on the disk 10A. For example, the head 15B includes a write head 15WB that writes data to the disk 10B and a read head 15RB that reads the data written on the disk 10B.

[0026] The driver IC 20 controls the driving of the SPM 12 and the VCM 14 according to the control of the system controller 130. In other words, the driver IC 20 controls the driving of the SPM 12 and the actuator 16 (actuators 16A and 16B) according to the control of the system controller 130. In addition, a plurality of driver ICs 20 may be provided according to the number of actuators 16. For example, the driver IC 20 may also include: a driver IC that controls the driving of the actuator 16A according to the control of the system controller 130 (for example, a microprocessor (Micro-processing unit: MPU) 60A described later), and a driver IC that controls the driving of the actuator 16B according to the control of the system controller 130 (for example, an MPU 60B described later).

[0027] The head amplifier IC (pre-amplifier) ​​30 includes a read amplifier and a write driver. The read amplifier amplifies the read signal read from the disk 10 (disks 10A and 10B) and outputs it to the system controller 130 (for example, read / write (R / W) channels 40A and 40B described later). The write driver outputs a write current corresponding to the signal output from the system controller 130 (for example, R / W channels 40A and 40B described later) to the head 15. In addition, a plurality of head amplifier ICs 30 may be provided according to the number of actuators 16. For example, the head amplifier IC 30 may include a head amplifier IC that performs signal processing on the read signal read from the disk 10A by the head 15A mounted on the actuator 16A, and a head amplifier IC having a read amplifier that performs signal processing on the read signal read from the disk 10B by the head 15B mounted on the actuator 16B.

[0028] The volatile memory 70 is a semiconductor memory that loses the stored data when the power supply is disconnected. The volatile memory 70 stores data required for processing of each part of the magnetic disk device 1. The volatile memory 70 is, for example, a DRAM (Dynamic Random Access Memory) or an SDRAM (Synchronous Dynamic Random Access Memory).

[0029] The nonvolatile memory 80 is a semiconductor memory that records stored data even when power supply is turned off. The nonvolatile memory 80 is, for example, a NOR-type or NAND-type flash ROM (Flash Read Only Memory: FROM).

[0030] The buffer memory 90 is a semiconductor memory that temporarily records data transmitted and received between the magnetic disk device 1 and the host 100. In addition, the buffer memory 90 may be formed integrally with the volatile memory 70. The buffer memory 90 is, for example, a DRAM, an SRAM (Static Random Access Memory), an SDRAM, a FeRAM (Ferroelectric Random Access Memory), or an MRAM (Magnetoresistive Random Access Memory).

[0031] The system controller (controller) 130 can be implemented, for example, using a large-scale integrated circuit (LSI) called a system-on-a-Chip (SoC) in which a plurality of components are integrated into a single chip. The system controller 130 is electrically connected to the driver IC 20, the head amplifier IC 30, the volatile memory 70, the buffer memory 90, the non-volatile memory 80, and the host system 100. The system controller 130 includes, for example, system controllers 130A and 130B. For example, the system controller 130A is electrically connected to the driver IC 20, the volatile memory 70, the buffer memory (cache) 50, the non-volatile memory 80, and the system controller 130B. In addition, the system controller 130A is connected to the host 100. For example, the system controller 130B is electrically connected to the driver IC 20, the head amplifier IC 30, and the system controller 130A. In addition, the system controller 130 may include three or more system controllers 130.

[0032] Figure 2 It is a schematic diagram showing a configuration example of the system controller 130 according to the present embodiment.

[0033] The system controller (controller) 130A includes a read / write (R / W) channel 40A, a hard disk controller (HDC) 50A, and a microprocessor (MPU) 60A. The system controller 130A is electrically connected to, for example, the driver IC 20, the head amplifier IC 30, the volatile memory 70, the nonvolatile memory 80, the buffer memory 90, the system controller 130B, and the host 100.

[0034] The R / W channel 40A performs signal processing of read data transmitted from the disk 10A to the host 100 and write data transmitted from the host 100 according to instructions from the MPU 60A described later. The R / W channel 40A has a circuit or function for measuring the signal quality of the read data. The R / W channel 40A is electrically connected to, for example, the head amplifier IC 30, the HDC 50A, and the MPU 60A.

[0035] HDC50A controls data transfer between host 100 and R / W channel 40A according to instructions from MPU60A described later. HDC50A is electrically connected to R / W channel 40A, MPU60A, system controller 130B, volatile memory 70, nonvolatile memory 80, buffer memory 90, host 100, etc.

[0036] MPU60A is a main controller that controls each part of the magnetic disk device 1. MPU60A performs: controlling the actuator 16A (VCM14A) via the driver IC20, and performing servo control for positioning the head 15A. MPU60A controls the write operation of writing data to the disk 10A, and selects the storage destination of the written data. In addition, MPU60A controls the read operation of reading data from the disk 10A, and controls the processing of the read data. MPU60A is connected to each part of the magnetic disk device 1. MPU60A is electrically connected to, for example, the driver IC20, the R / W channel 40A, and the HDC50A.

[0037] The MPU 60A includes a read / write control unit 610A, an internal log management unit 620A, and a refresh processing unit 630A. The MPU 60A executes the processing of these units such as the read / write control unit 610A, the internal log management unit 620A, and the refresh processing unit 630A on the firmware. In addition, the MPU 60A may also include these units such as the read / write control unit 610A, the internal log management unit 620A, and the refresh processing unit 630A as circuits.

[0038] The read / write control unit 610A controls the reading and writing of data according to the command from the host 100. The read / write control unit 610A controls the VCM 14 via the driver IC 20 to position the head 15A at the target position on the disk 10A to read or write data. Hereinafter, the term "access" may also be used to include the meaning of "recording or writing data to a predetermined area", "reading or reading data from a predetermined area", and "moving the head 15 etc. to a predetermined area".

[0039] The internal log management unit 620A manages the state of the magnetic disk device 1, such as the data written on the disk 10, and the data used to confirm the health of the head 15 (hereinafter sometimes referred to as the internal log). The internal log includes data used in SMART (Self-Monitoring, Analysis and Reporting Technology), data associated with defects (such as defects) of the disk 10A, and the degree or number of times (hereinafter sometimes referred to as the number of ATI times) of the influence (Adjacent Track Interference: ATI) of the leakage flux from the head 15A when data is written in the periphery. The internal log management unit 620A manages the internal log as a table. The internal log management unit 620A expands (configures or temporarily saves) the table of the internal log corresponding to the actuator 16A (disk 10A, head 15A and system controller 130A) (hereinafter sometimes referred to as the internal log table) TBA to a volatile recording area, such as the volatile memory 70, and performs processing such as updating. For example, when the internal log table TBA is a table of ATI times associated with ATI (hereinafter sometimes referred to as an ATI management table), the internal log management unit 620A adds a predetermined value, such as 1, to the ATI times corresponding to the predetermined track in the internal log table TBA expanded to the volatile memory 70, whenever data is written a predetermined number of times, such as 1, to a track located in the radial direction of a predetermined track, such as a track adjacent to the predetermined track in the radial direction (hereinafter sometimes referred to as an adjacent track). Here, "adjacent" of course includes data, objects, areas, and spaces that are arranged in contact, and also includes arranging with a predetermined interval. In addition, when the internal log table TBA is an ATI management table and data is written to a predetermined track, the internal log management unit 620A clears the ATI times corresponding to the predetermined track in the internal log table TBA expanded to the volatile memory 70, such as setting it to 0.

[0040] The internal log management unit 620A periodically records the internal log table TBA expanded to a volatile recording area, such as the volatile memory 70, to a nonvolatile recording area, such as the system area 10A2 of the disk 10A. When the internal log management unit 620A records the internal log table TBA expanded to a volatile recording area, such as the volatile memory 70, to a nonvolatile recording area, such as the system area 10A2 of the disk 10A, it adds a timestamp to the internal log table TBA and records it to the system area 10A2 of the disk 10A. The timestamp is equivalent to data indicating the time when predetermined data is recorded to a predetermined recording area. For example, the timestamp is expressed by the total time of supplying power (current or voltage) to the magnetic disk device 1. Therefore, the larger the timestamp, the newer the internal log table, and the smaller the timestamp, the older the internal log table. That is, the internal log table with the largest timestamp among the multiple internal log tables with timestamps is equivalent to the latest internal log table, and the internal log table with the smallest timestamp among the multiple internal log tables with timestamps is equivalent to the oldest internal log table.

[0041] When the system controller 130A is in a state where many commands are processed by the system controller 130A, or when the frequency of access to the disk 10A is high by driving the actuator 16A, that is, when the system controller 130A is in a busy state, the internal log management unit 620A writes the internal log table TBA to the system area of ​​the other disk 10 other than the disk 10A corresponding to the system controller 130A, such as when few commands are processed by the system controller 130A, when no commands are processed by the system controller 130A, when the frequency of access to the disk 10A is low by driving the actuator 16A, or when the system controller 130A is in an idle state, that is, when the system controller 130A is not in the busy state. The "access frequency" indicates how many times a predetermined area is accessed within a predetermined time (how high the access frequency is) or how few times a predetermined area is accessed within a predetermined time (how low the access frequency is).

[0042] When the system controller 130A is not in the Busy state, the internal log management unit 620A writes the internal log table corresponding to other actuators 16 other than the actuator 16A controlled by other system controllers 130 other than the system controller 130A in the Busy state (other disks 10 other than the disk 10A, other heads 15 other than the head 15A, or other controllers 130 other than the system controller 130B), such as the internal log table TBB corresponding to the actuator 16B (disk 10B, head 15B, and system controller 130B) described later, to a non-volatile recording area, such as the system area 10A2 of the disk 10A. In addition, the internal log management unit 620A may also write the internal log table TBA to a non-volatile recording area, such as the system area 10A2 of the disk 10A, when the system controller 130A is not in the Busy state.

[0043] When the power of the magnetic disk device 1 is disconnected (OFF) or the power of the magnetic disk device 1 is cut off, the internal log management unit 620A clears, for example, to 0, the ATI times corresponding to each track of the disk 10A contained in the internal log table TBA, for example, the ATI management table TBA, which is recorded in a volatile recording area such as the volatile memory 70.

[0044] When the power of the magnetic disk device 1 is turned on (ON) (hereinafter sometimes referred to as startup), the internal log management unit 620A detects the time stamp assigned to the internal log table TBA corresponding to the actuator 16A (disk 10A, head 15A, and system controller 130A) recorded in all non-volatile recording areas, such as all system areas of the disk 10, and generates (constructs or reconstructs) an internal log table including the latest (for example, the largest) time stamp in a volatile recording area, such as the volatile memory 70. In addition, the internal log management unit 620A may update the internal log table TBA recorded in all or part of the non-volatile recording area, such as the system area of ​​the disk 10, to the internal log table TBA generated (constructed or reconstructed) in the volatile recording area, such as the volatile memory 70 at startup.

[0045] The refresh processing unit 630A performs the following processing (hereinafter sometimes referred to as refresh processing): temporarily reading the data written in the predetermined recording area and rewriting the read data to the predetermined recording area. The refresh processing unit 630A refers to the internal log table TBA equivalent to the ATI management table, and when the number of ATIs corresponding to a predetermined track of the disk 10A exceeds a predetermined threshold value (hereinafter sometimes referred to as refresh threshold value), the refresh processing is performed on the track.

[0046] The system controller (controller) 130B includes an R / W channel 40B, a hard disk controller (HDC) 50B, and an MPU 60B. The system controller 130B is electrically connected to, for example, the driver IC 20, the head amplifier IC 30, and the system controller 130A. The system controller 130B is electrically connected to the nonvolatile memory 70, the nonvolatile memory 80, the buffer memory 90, and the host 100 via the system controller 130A.

[0047] The R / W channel 40B performs signal processing of read data transmitted from the disk 10B to the host 100 and write data transmitted from the host 100 according to instructions from the MPU 60B described later. The R / W channel 40B has a circuit or function for measuring the signal quality of the read data. The R / W channel 40B is electrically connected to, for example, the head amplifier IC 30, the HDC 50B, and the MPU 60B.

[0048] The HDC 50B controls data transfer between the host 100 and the R / W channel 40B via the HDC 50A according to instructions from the MPU 60B described later. The HDC 50B is electrically connected to the R / W channel 40B, the MPU 60B, and the system controller 130A (HDC 50A), for example.

[0049] MPU60B is a main controller that controls each part of the magnetic disk device 1. MPU60B performs servo control to control actuator 16B (VCM14B) via driver IC20 and to position head 15B. MPU60B controls the writing operation of writing data to disk 10B and selects the storage destination of the written data. In addition, MPU60B controls the reading operation of reading data from disk 10B and controls the processing of the read data. MPU60B is connected to each part of magnetic disk device 1. MPU60B is electrically connected to driver IC20, R / W channel 40B, HDC50B, etc., for example.

[0050] The MPU 60B includes a read / write control unit 610B, an internal log management unit 620B, a refresh processing unit 630B, etc. The MPU 60B executes the processing of these units such as the read / write control unit 610B, the internal log management unit 620B, and the refresh processing unit 630B on the firmware. In addition, the MPU 60B may also include these units such as the read / write control unit 610B, the internal log management unit 620B, and the refresh processing unit 630B as a circuit.

[0051] The read / write control unit 610B controls data reading and writing according to commands from the host 100. The read / write control unit 610B controls the VCM 14 via the driver IC 20 to position the head 15B at a target position on the disk 10B to read or write data.

[0052] The internal log management unit 620B manages the internal log. The internal log management unit 620B manages the internal log as a table. The internal log management unit 620B expands (configures or temporarily stores) the internal log table TBB corresponding to the actuator 16B (disk 10B, head 15B, and system controller 130B) to a volatile recording area, such as the volatile memory 70, to perform processing such as updating. For example, when the internal log table TBB is an ATI management table, the internal log management unit 620B adds a predetermined value, such as 1, to the ATI number corresponding to the track in the radial direction of the predetermined track, such as an adjacent track of the track, each time data is written a predetermined number of times, such as 1. Furthermore, when the internal log table TBB is an ATI management table and data is written to a predetermined track, the internal log management unit 620B clears the ATI count corresponding to the predetermined track in the internal log table TBB expanded to the volatile memory 70 and sets it to 0, for example.

[0053] The internal log management unit 620B periodically records the internal log table TBB expanded to a volatile recording area, such as the volatile memory 70, to a non-volatile recording area, such as the system area 10B2 of the disk 10B. When the internal log management unit 620B records the internal log table TBB expanded to a volatile recording area, such as the volatile memory 70, to a non-volatile recording area, such as the system area 10B2 of the disk 10B, the internal log management unit 620B gives a time stamp to the internal log table TBB and records it in the system area 10B2 of the disk 10B.

[0054] When the system controller 130B is in the Busy state, the internal log management unit 620B writes the internal log table TBB to the system area of ​​another disk 10 other than the disk 10B corresponding to the system controller 130 that is not in the Busy state, for example, the system area 10A2 of the disk 10A.

[0055] When the system controller 130B is not in the Busy state, the internal log management unit 620B writes the internal log table corresponding to other actuators 16 other than the actuator 16B controlled by other system controllers 130 other than the system controller 130B in the Busy state (other disks other than the disk 10B, other heads other than the head 15B, or other system controllers other than the system controller 130B), such as the internal log table TBA corresponding to the actuator 16A (disk 10A, head 15A, and system controller 130A), to a non-volatile recording area such as the system area 10B2 of the disk 10B. In addition, the internal log management unit 620B may also write the internal log table TBB to a non-volatile recording area such as the system area 10B2 of the disk 10B when the system controller 130B is not in the Busy state.

[0056] When the power of the magnetic disk device 1 is disconnected or the power of the magnetic disk device 1 is cut off, the internal log management unit 620B clears the ATI times corresponding to each track of the disk 10B contained in the internal log table TBB recorded in a volatile recording area such as the volatile memory 70, for example, to 0.

[0057] When the power of the magnetic disk device 1 is turned on, the internal log management unit 620B detects the time stamp given to the internal log table TBB corresponding to the actuator 16B (disk 10B, head 15B and system controller 130B) recorded in all non-volatile recording areas, such as all system areas of the disk 10, and generates (constructs or reconstructs) an internal log table including the latest (for example, the largest) time stamp in a volatile recording area, such as the volatile memory 70. In addition, the internal log management unit 620B may update the internal log table TBB recorded in all or part of the non-volatile recording area, such as the system area of ​​the disk 10, to the internal log table TBB generated (constructed or reconstructed) in the volatile recording area, such as the volatile memory 70 at the time of startup.

[0058] The refresh processing unit 630B performs refresh processing. The refresh processing unit 630B refers to the internal log table TBB corresponding to the ATI management table, and when the number of ATIs corresponding to a predetermined track of the disk 10B exceeds the refresh threshold, performs refresh processing on the track.

[0059] Figure 3 This is a schematic diagram showing an example of the number of ATIs added to the surrounding area according to the number of times data is written to a predetermined track 0. The horizontal axis represents the relative track position relative to the track to which data is written, and the vertical axis represents the number of ATIs added when data is written once to the track corresponding to the horizontal axis 0. Figure 3The lines in the middle represent a plurality of ATI orders measured using a plurality of heads having different characteristics.

[0060] exist Figure 3 In the example shown, when writing is performed once on a predetermined track, the number of ATIs of at least the adjacent tracks is increased by 1.

[0061] Figure 4 FIG. 1 is a diagram showing an example of internal log tables TBA and TBB. Figure 4 In the example, the internal log tables TBA and TBB are equivalent to the ATI management tables.

[0062] exist Figure 4 In the example shown, the internal log tables (ATI management tables) TBA and TBB include a head (HEAD) number, a time stamp (Time Stamp) [sec], and an ATI count corresponding to each cylinder (Cly) (track) of each disk 10A and 10B.

[0063] Figure 5 It is a schematic diagram showing an example of a management method of the internal log tables TBA and TBB according to the present embodiment.

[0064] exist Figure 5 In the example shown, when the system controller 130A is in the Busy state and is about to record the internal log table TBA expanded to the volatile memory 70 to the system area 10A2 of the disk 10A, the system controller 130B which is not in the Busy state records the internal log table TBA with a timestamp to the system area 10B2 of the disk 10B.

[0065] exist Figure 5 In the example shown, when the system controller 130B is in the Busy state at the time of recording the internal log table TBB expanded to the volatile memory 70 to the system area 10B2 of the disk 10B, the internal log table TBB with a timestamp is recorded to the system area 10A2 of the disk 10A via the system controller 130A which is not in the Busy state.

[0066] Figure 6 It is a schematic diagram showing an example of a management method of the internal log tables TBA and TBB according to the present embodiment.

[0067] exist Figure 6 In the example shown, the system controller 130A records the internal log table TBA with a timestamp in the system area 10A2 of the disk 10A when the timing for recording the internal log table TBA expanded to the volatile memory 70 in the system area 10A2 of the disk 10A is not in the Busy state.

[0068] exist Figure 6 In the example shown, when the system controller 130A is in the Busy state and is about to record the internal log table TBA expanded to the volatile memory 70 to the system area 10A2 of the disk 10A, the system controller 130B which is not in the Busy state records the internal log table TBA with a timestamp to the system area 10B2 of the disk 10B.

[0069] exist Figure 6 In the example shown, the system controller 130B records the internal log table TBB with a timestamp in the system area 10B2 of the disk 10B when the timing for recording the internal log table TBB expanded to the volatile memory 70 in the system area 10B2 of the disk 10B is not in the Busy state.

[0070] exist Figure 6 In the example shown, when the system controller 130B is in the Busy state and is about to record the internal log table TBB expanded to the volatile memory 70 in the system area 10B2 of the disk 10B, the internal log table TBB with a timestamp is recorded in the system area 10A2 of the disk 10A via the system controller 130A which is not in the Busy state.

[0071] Figure 7 This is a flowchart showing an example of a method for managing the internal log table according to the present embodiment.

[0072] The system controller 130 reads the internal log table (hereinafter sometimes referred to as the target internal log table) corresponding to the actuator (hereinafter sometimes referred to as the target actuator) 16 controlled by the target system controller (hereinafter sometimes referred to as the target system controller) 130, the disk 10 (hereinafter sometimes referred to as the target disk 10) corresponding to the target system controller 130, and the head 15 (hereinafter sometimes referred to as the target head 15) corresponding to the target system controller 130 from the predetermined nonvolatile recording area, such as the system area, of all the disks 10 (B701). The system controller 130 expands (or configures) the latest target internal log table among the plurality of target internal log tables recorded in the predetermined nonvolatile recording area, such as the system area, of the plurality of disks 10 in the predetermined volatile recording area, such as the volatile memory 70 (B702). For example, the system controller 130 expands (or configures) the target internal log table with the largest time stamp among the plurality of target internal log tables recorded in the predetermined nonvolatile recording area, such as the system area, of the plurality of disks 10 in the predetermined volatile recording area, such as the volatile memory 70. The system controller 130 determines whether the target system controller 130 is in a busy state or not in a busy state (B703). When it is determined that the target system controller 130 is not in a busy state (B703: No), the system controller 130 writes the target internal log table corresponding to the target system controller 130 recorded in a predetermined volatile recording area, such as the volatile memory 70, to a predetermined non-volatile recording area, such as the system area, of the target disk 10 (B704), and ends the processing. When it is determined that the target system controller 130 is in a busy state (B703: Yes), the system controller 130 writes the target internal log table recorded in a predetermined volatile recording area, such as the volatile memory 70, to a predetermined non-volatile recording area, such as the system area, of other disks other than the target disk 10 corresponding to other actuators 16 other than the target actuator 16 controlled by other system controllers 130 other than the target system controller 130 not in a busy state (B705), and ends the processing.

[0073] According to the present embodiment, when the target system controller 130 is in the Busy state, the magnetic disk device 1 records the target internal log table corresponding to the target disk 10, the target head 15, the target actuator 16, the target system controller 130, etc., in the system area of ​​the other disk 10 other than the target disk 10 corresponding to the other system controllers 130 other than the target system controller 130 that is not in the Busy state. The magnetic disk device 1 can generate (construct or reconstruct) the target internal log table in the volatile memory 70 based on the target internal log table corresponding to the target disk 10, the target head 15, the target actuator 16, the target system controller 130, etc. recorded in the system area of ​​the predetermined disk 10 after the power is turned off or the power is turned on again after being turned off. Therefore, the magnetic disk device 1 can improve the reliability of data while maintaining the performance of the write / read process.

[0074] Next, a magnetic disk device according to a modified example of the embodiment will be described. In the modified example, the same reference numerals are used to denote the same components as those of the above-described embodiment, and detailed description thereof will be omitted.

[0075] (Variant 1)

[0076] The magnetic disk device 1 according to Modification 1 is different from the magnetic disk device 1 according to the above-described embodiment in the number of actuators.

[0077] The disk 10 includes, for example, disks 10A, 10B, and 10C. In addition, the disk 10 may include four or more disks. In addition, the disk 10C may include two or more disks. The head 15 includes, for example, heads 15A, 15B, and 15C. In addition, the head 15 may include four or more heads. In addition, the head 15C may include two or more heads.

[0078] The actuator 16 includes actuators 16A, 16B, and 16C. In addition, the actuator 16 may include more than four actuators. The actuator 16C is mounted on a common pivot and can rotate independently around the pivot. The actuator 16C controls the head 15C mounted on the arm to move to a predetermined position of the disk 10C through the drive of the VCM. In addition, the actuator 16C may also include the head 15C, the driver IC 20, and the head amplifier IC 30.

[0079] The disk 10 allocates a user data area that can be used by the user and a system area for writing information required for system management to the area where data can be written. For example, the disk 10A is allocated with a user data area 10A1 and a system area 10A2. The disk 10B is allocated with a user data area 10B1 and a system area 10B2. Hereinafter, the direction perpendicular to the radial direction of the disk 10 is referred to as the circumferential direction.

[0080] The system controller 130 includes, for example, system controllers 130A, 130B, and 130C. For example, the system controller 130C is electrically connected to the driver IC 20 , the head amplifier IC 30 , and the system controller 130B. Alternatively, the system controller 130 may include four or more system controllers 130 .

[0081] Figure 8 1 is a schematic diagram showing a configuration example of the system controller 130 according to Modification 1.

[0082] The system controller (controller) 130C includes a read / write (R / W) channel 40C, an HDC 50C, and an MPU 60C. The system controller 130C is electrically connected to, for example, the driver IC 20, the head amplifier IC 30, the volatile memory 70, the nonvolatile memory 80, the buffer memory 90, and the system controller 130B.

[0083] The R / W channel 40C performs signal processing of read data transmitted from the disk 10C to the host 100 and write data transmitted from the host 100 according to instructions from the MPU 60C ​​described later. The R / W channel 40C has a circuit or function for measuring the signal quality of the read data. The R / W channel 40C is electrically connected to, for example, the head amplifier IC 30, the HDC 50C, and the MPU 60C.

[0084] The HDC 50C controls data transfer between the host 100 and the R / W channel 40C according to instructions from the MPU 60C ​​described later. The HDC 50C is electrically connected to the R / W channel 40C, the MPU 60C, and the system controller 130B, for example.

[0085] The MPU 60C ​​is a main controller that controls each part of the magnetic disk device 1. The MPU 60C ​​performs servo control to control the actuator 16C (VCM) via the driver IC 20 and to position the head 15C. The MPU 60C ​​controls the writing operation of writing data to the disk 10C and selects the storage destination of the written data. In addition, the MPU 60C ​​controls the reading operation of reading data from the disk 10C and controls the processing of the read data. The MPU 60C ​​is connected to each part of the magnetic disk device 1. For example, the MPU 60C ​​is electrically connected to the driver IC 20, the R / W channel 40C, and the HDC 50C.

[0086] The MPU 60C ​​includes a read / write control unit 610C, an internal log management unit 620C, and a refresh processing unit 630C. The MPU 60C ​​executes the processing of these units such as the read / write control unit 610C, the internal log management unit 620C, and the refresh processing unit 630C on the firmware. In addition, the MPU 60C ​​may also include these units such as the read / write control unit 610C, the internal log management unit 620C, and the refresh processing unit 630C as circuits.

[0087] The read / write control unit 610C controls data reading and writing according to commands from the host 100. The read / write control unit 610C controls the VCM 14 via the driver IC 20 to position the head 15C at a target position on the disk 10C to read or write data.

[0088] The internal log management unit 620C manages the internal log. The internal log management unit 620C manages the internal log as a table. The internal log management unit 620C expands (configures or temporarily stores) the internal log table TBC corresponding to the actuator 16C (disk 10C, head 15C, and system controller 130C) to a volatile recording area, such as the volatile memory 70, to perform update and other processing. For example, when the internal log table TBC is an ATI management table, the internal log management unit 620C adds a predetermined value, such as 1, to the ATI number corresponding to the track in the radial direction of the predetermined track, such as an adjacent track of the track, each time data is written a predetermined number of times, such as 1, to the internal log table TBC expanded to the volatile memory 70.

[0089] The internal log management unit 620C periodically records the internal log table TBC expanded to a volatile recording area, such as the volatile memory 70, to a nonvolatile recording area, such as the system area 10C2 of the disk 10C. When recording the internal log table TBC expanded to a volatile recording area, such as the volatile memory 70, to a nonvolatile recording area, such as the system area 10C2 of the disk 10C, the internal log management unit 620C gives a time stamp to the internal log table TBC and records it to the system area 10C2 of the disk 10C.

[0090] When the system controller 130C is in the Busy state, the internal log management unit 620C writes the internal log table TBC to the system area of ​​other disks 10 other than the disk 10C corresponding to the system controller 130 that is not in the Busy state, for example, the system area 10A2 of the disk 10A and / or the system area 10B2 of the disk 10B.

[0091] When the system controller 130C is not in the Busy state, the internal log management unit 620C writes the internal log table corresponding to other actuators 16 other than the actuator 16C controlled by other system controllers 130 other than the system controller 130C in the Busy state (other disks 10 other than the disk 10C, other heads 15 other than the head 15C, or other controllers 130 other than the system controller 130C), such as the internal log table TBC corresponding to the actuator 16C (disk 10C, head 15C, and system controller 130C) described later, to a non-volatile recording area, such as the system area 10C2 of the disk 10C. Alternatively, the internal log management unit 620C may write the internal log table TBC to a non-volatile recording area, such as the system area 10C2 of the disk 10C, when the system controller 130C is not in the Busy state.

[0092] When the power of the magnetic disk device 1 is disconnected or the power of the magnetic disk device 1 is cut off, the internal log management unit 620C clears the ATI times corresponding to each track of the disk 10C contained in the internal log table TBC recorded in a volatile recording area such as the volatile memory 70, for example, to 0.

[0093] When the power of the magnetic disk device 1 is turned on, the internal log management unit 620C detects the time stamp assigned to the internal log table TBC corresponding to the actuator 16C (disk 10C, head 15C, and system controller 130C) recorded in all non-volatile recording areas, such as all system areas of the disk 10, and generates (constructs or reconstructs) an internal log table including the latest (for example, the largest) time stamp in a volatile recording area, such as the volatile memory 70. In addition, the internal log management unit 620C may update the internal log table TBC recorded in all or part of the non-volatile recording area, such as the system area of ​​the disk 10, to the internal log table TBC generated (constructed or reconstructed) in the volatile recording area, such as the volatile memory 70 at the time of startup.

[0094] The refresh processing unit 630C performs refresh processing. The refresh processing unit 630C refers to the internal log table TBC corresponding to the ATI management table, and when the number of ATIs corresponding to a predetermined track of the disk 10C exceeds the refresh threshold, performs refresh processing on the track.

[0095] Fig. 9 This is a schematic diagram showing an example of a management method of the internal log tables TBA, TBB, and TBC according to the first modification.

[0096] exist Fig. 9In the example shown, when the system controller 130A is in the Busy state and is about to record the internal log table TBA expanded to the volatile memory 70 to the system area 10A2 of the disk 10A, the system controller 130B which is not in the Busy state records the internal log table TBA with a timestamp to the system area 10B2 of the disk 10B.

[0097] exist Fig. 9 In the example shown, when the system controller 130B is in the Busy state and is about to record the internal log table TBB expanded to the volatile memory 70 to the system area 10B2 of the disk 10B, the system controller 130C which is not in the Busy state records the internal log table TBB with a timestamp to the system area 10C2 of the disk 10C.

[0098] exist Fig. 9 In the example shown, when the system controller 130C is in the Busy state and is about to record the internal log table TBC expanded to the volatile memory 70 to the system area 10C2 of the disk 10C, the internal log table TBC with a timestamp is recorded to the system area 10A2 of the disk 10A via the system controller 130A which is not in the Busy state.

[0099] Fig.10 This is a schematic diagram showing an example of a management method of the internal log tables TBA, TBB, and TBC according to the first modification.

[0100] exist Fig.10 In the example shown, when the system controller 130A is in the Busy state and is about to record the internal log table TBA expanded to the volatile memory 70 to the system area 10A2 of the disk 10A, the system controller 130B which is not in the Busy state records the internal log table TBA with a timestamp to the system area 10B2 of the disk 10B.

[0101] exist Fig.10 In the example shown, when the system controller 130A is in the Busy state when recording the internal log table TBA expanded to the volatile memory 70 to the system area 10A2 of the disk 10A, the system controller 130C which is not in the Busy state records the internal log table TBA with a timestamp to the system area 10C2 of the disk 10C.

[0102] exist Fig.10In the example shown, when the system controller 130B is in the Busy state and is about to record the internal log table TBB expanded to the volatile memory 70 to the system area 10B2 of the disk 10B, the system controller 130C which is not in the Busy state records the internal log table TBB with a timestamp to the system area 10C2 of the disk 10C.

[0103] exist Fig.10 In the example shown, when the system controller 130B is in the Busy state at the time of recording the internal log table TBB expanded to the volatile memory 70 to the system area 10B2 of the disk 10B, the internal log table TBB with a timestamp is recorded to the system area 10A2 of the disk 10A via the system controller 130A which is not in the Busy state.

[0104] exist Fig.10 In the example shown, when the system controller 130C is in the Busy state and is about to record the internal log table TBC expanded to the volatile memory 70 to the system area 10C2 of the disk 10C, the internal log table TBC with a timestamp is recorded to the system area 10A2 of the disk 10A via the system controller 130A which is not in the Busy state.

[0105] exist Fig.10 In the example shown, when the system controller 130C is in the Busy state and is about to record the internal log table TBC expanded to the volatile memory 70 to the system area 10C2 of the disk 10C, the system controller 130B which is not in the Busy state records the internal log table TBC with a timestamp to the system area 10B2 of the disk 10B.

[0106] Fig.11 This is a schematic diagram showing an example of a management method of the internal log tables TBA, TBB, and TBC according to the first modification.

[0107] exist Fig.11 In the example shown, the system controller 130A records the internal log table TBA with a timestamp in the system area 10A2 of the disk 10A when the timing for recording the internal log table TBA expanded to the volatile memory 70 in the system area 10A2 of the disk 10A is not in the Busy state.

[0108] exist Fig.11In the example shown, when the system controller 130A is in the Busy state and is about to record the internal log table TBA expanded to the volatile memory 70 to the system area 10A2 of the disk 10A, the system controller 130B which is not in the Busy state records the internal log table TBA with a timestamp to the system area 10B2 of the disk 10B.

[0109] exist Fig.11 In the example shown, when the system controller 130A is in the Busy state when recording the internal log table TBA expanded to the volatile memory 70 to the system area 10A2 of the disk 10A, the system controller 130C which is not in the Busy state records the internal log table TBA with a timestamp to the system area 10C2 of the disk 10C.

[0110] exist Fig.11 In the example shown, the system controller 130B records the internal log table TBB with a timestamp in the system area 10B2 of the disk 10B when the timing for recording the internal log table TBB expanded to the volatile memory 70 in the system area 10B2 of the disk 10B is not in the Busy state.

[0111] exist Fig.11 In the example shown, when the system controller 130B is in the Busy state and is about to record the internal log table TBB expanded to the volatile memory 70 to the system area 10B2 of the disk 10B, the system controller 130C which is not in the Busy state records the internal log table TBB with a timestamp to the system area 10C2 of the disk 10C.

[0112] exist Fig.11 In the example shown, when the system controller 130B is in the Busy state at the time of recording the internal log table TBB expanded to the volatile memory 70 to the system area 10B2 of the disk 10B, the internal log table TBB with a timestamp is recorded to the system area 10A2 of the disk 10A via the system controller 130A which is not in the Busy state.

[0113] exist Fig.11 In the example shown, the system controller 130C records the internal log table TBC with a timestamp in the system area 10C2 of the disk 10C when the timing for recording the internal log table TBC expanded to the volatile memory 70 in the system area 10C2 of the disk 10C is not in the Busy state.

[0114] exist Fig.11In the example shown, when the system controller 130C is in the Busy state and is about to record the internal log table TBC expanded to the volatile memory 70 to the system area 10C2 of the disk 10C, the internal log table TBC with a timestamp is recorded to the system area 10A2 of the disk 10A via the system controller 130A which is not in the Busy state.

[0115] exist Fig.11 In the example shown, when the system controller 130C is in the Busy state and is about to record the internal log table TBC expanded to the volatile memory 70 to the system area 10C2 of the disk 10C, the system controller 130B which is not in the Busy state records the internal log table TBC with a timestamp to the system area 10B2 of the disk 10B.

[0116] According to the first modification, the magnetic disk device 1 can improve the reliability of data while maintaining the performance of the write / read processing.

[0117] Several embodiments have been described above, but these embodiments are provided as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. These embodiments and their variations are included in the scope and purpose of the invention, and are included in the invention described in the claims and their equivalents.

[0118] An example of a magnetic disk device and an information management method obtained according to the configuration disclosed in this specification is appended below. (1)

[0120] A magnetic disk device comprising:

[0121] A first disk having a first user data area in which user data is written and a first system area different from the first user data area;

[0122] a second disk having a second user data area in which user data is written and a second system area different from the second user data area;

[0123] a first head for writing data to the first disk and reading data from the first disk;

[0124] a second head for writing data to the second disk and reading data from the second disk;

[0125] a first actuator having the first head;

[0126] a second actuator having the second head;

[0127] a first controller that controls the first disk, the first head, and the first actuator; and

[0128] a second controller that controls the second disk, the second head, and the second actuator,

[0129] The first controller records first information associated with the first head and the first disk in the second system area. (2)

[0131] The magnetic disk device according to (1),

[0132] The first controller records the first information in the first system area. (3)

[0134] According to the magnetic disk device described in (2),

[0135] It also has volatile memory.

[0136] The first controller records the first information in the volatile memory. (4)

[0138] According to the magnetic disk device described in (3),

[0139] The first controller periodically records the first information updated in the volatile memory and time-stamped in at least one of the first system area and the second system area. (5)

[0141] According to the magnetic disk device described in (4),

[0142] When the first controller processes many commands and the second controller processes few commands, the first controller records the first information updated in the volatile memory and given a time stamp in the second system area. (6)

[0144] According to the magnetic disk device described in (5),

[0145] When the number of commands processed by the first controller is small, the first controller records the first information updated in the volatile memory and time-stamped in the first system area. (7)

[0147] According to the magnetic disk device described in (6),

[0148] The first controller records, in the volatile memory at the time of activation, the first information recorded in the first system area and the first information recorded in the second system area, the first information having a larger time stamp. (8)

[0150] The magnetic disk device according to any one of (1) to (7),

[0151] The first information corresponds to a table indicating the degree of influence of leakage magnetic flux according to the number of times data is written to the radially adjacent regions of the first disk. (9)

[0153] The magnetic disk device according to any one of (1) to (8),

[0154] The second controller records the second information associated with the second head and the second disk in the first system area. (10)

[0156] According to the magnetic disk device described in (9),

[0157] The second controller records the second information in the volatile memory. (11)

[0159] The magnetic disk device according to (10),

[0160] The second controller periodically records the second information updated in the volatile memory and time-stamped in at least one of the first system area and the second system area. (12)

[0162] The magnetic disk device according to (11),

[0163] When the second controller processes many commands and the first controller processes few commands, the second controller records the second information updated in the volatile memory and time-stamped in the first system area. (13)

[0165] The magnetic disk device according to (12),

[0166] When the number of commands processed by the second controller is small, the second controller records the second information updated in the volatile memory and time-stamped in the second system area. (14)

[0168] According to the magnetic disk device described in (13),

[0169] The second controller records, in the volatile memory at the time of activation, the second information recorded in the first system area and the second information recorded in the second system area, the second information having a larger time stamp. (15)

[0171] The magnetic disk device according to any one of (9) to (14),

[0172] The second information corresponds to a table indicating the degree of influence of leakage magnetic flux according to the number of times data is written to the radially adjacent regions of the disk. (16)

[0174] A magnetic disk device comprising:

[0175] a plurality of disks, each having a user data area for writing user data and a system area different from the user data area;

[0176] a plurality of heads, which respectively write data to the plurality of disks and respectively read data from the plurality of disks;

[0177] a plurality of actuators, each having the plurality of heads; and

[0178] a plurality of controllers that control the plurality of disks, the plurality of heads, and the plurality of actuators,

[0179] The first controller among the multiple controllers records the first information associated with the first head among the multiple heads controlled by the first controller and the first disk facing the first head among the multiple disks in the system area of ​​other disks other than the first disk among the multiple disks. (17)

[0181] An information management method is applied to a magnetic disk device, the magnetic disk device comprising: a plurality of disks each having a user data area for writing user data and a system area different from the user data area; a plurality of heads for writing data to the plurality of disks and reading data from the plurality of disks; a plurality of actuators each having the plurality of heads; and a plurality of controllers for controlling the plurality of disks, the plurality of heads, and the plurality of actuators, the information management method comprising:

[0182] First information associated with a first head among the plurality of heads and a first disk facing the first head among the plurality of disks is recorded in a system area of ​​a disk other than the first disk among the plurality of disks.

Claims

1. A magnetic disk device comprising: A first disk having a first user data area in which user data is written and a first system area different from the first user data area; a second disk having a second user data area in which user data is written and a second system area different from the second user data area; a first head for writing data to the first disk and reading data from the first disk; a second head for writing data to the second disk and reading data from the second disk; a first actuator having the first head; a second actuator having the second head; a first controller that controls the first disk, the first head, and the first actuator; and a second controller that controls the second disk, the second head, and the second actuator, The first controller records first information associated with the first head and the first disk in the second system area via the second controller.

2. The magnetic disk device according to claim 1, The first controller records the first information in the first system area.

3. The magnetic disk device according to claim 2, It also has volatile memory. The first controller records the first information in the volatile memory.

4. The magnetic disk device according to claim 3, The first controller periodically records the first information updated in the volatile memory and timestamped in the first system area, or the second controller periodically records the first information updated in the volatile memory and timestamped in the second system area.

5. The magnetic disk device according to claim 4, When the first controller processes more commands than the second controller processes fewer commands, the first controller records the first information updated in the volatile memory and given a time stamp in the second system area.

6. The magnetic disk device according to claim 5, When there are few commands to be processed by the first controller, the first controller records the first information updated in the volatile memory and given a time stamp in the first system area.

7. The magnetic disk device according to claim 6, The first controller records, in the volatile memory at the time of activation, the first information recorded in the first system area and the first information recorded in the second system area, the first information having a larger time stamp.

8. The magnetic disk device according to any one of claims 1 to 7, The first information is a table indicating the degree of influence of leakage magnetic flux according to the number of times data is written to the radially adjacent areas of the first disk.

9. A magnetic disk device comprising: a plurality of disks, each having a user data area for writing user data and a system area different from the user data area; a plurality of heads, which respectively write data to the plurality of disks and respectively read data from the plurality of disks; a plurality of actuators, each having the plurality of heads; as well as a plurality of controllers that control the plurality of disks, the plurality of heads, and the plurality of actuators, The first controller records the first information associated with the first head among the multiple heads controlled by the first controller and the first disk opposite to the first head among the multiple disks into the system area of ​​other disks other than the first disk among the multiple disks via other controllers other than the first controller among the multiple controllers.

Images