JP2017174494A - Disk storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk storage device and method with which it is possible to improve processing efficiency when rewriting data.SOLUTION: A disk storage device according to the present embodiment comprises a disk that includes a first area in which data is recorded using a recording system that records data in a track area and records data in a track area that partly overlaps said track area and a second area for caching data, and executes control to receive a first write command including contiguous first address information and first data and record the first data in the second area, control to receive a second write command including a plurality of noncontiguous second address information and a plurality of second data and record the second data in the second area, and control to receive a third write command including contiguous third address information that follows the first address information and third data and record the third data in the first area.SELECTED DRAWING: Figure 1

Description

Embodiments described herein relate generally to a disk storage device having a single dwrite function.

In recent years, in the field of hard disk drives (hereinafter sometimes simply referred to as disk drives), as a method for increasing the recording density of a disk as a recording medium, a so-called single write (also called shingled write) method is used. A so-called data writing method has been developed.

In the single write method, since data is overwritten with a write head width wider than the read track width on the disk, one side of the recorded track is erased. For this reason, rewriting operation in units of tracks cannot be performed, and it is necessary to rewrite in units of recording areas (bands described later) composed of a plurality of tracks. Therefore, a considerable processing time is required as compared with the conventional rewriting process.

As a method for improving the efficiency of such rewriting processing, a method using both a media cache and a spare band has been proposed. The media cache is a temporary recording area (buffer area) using a designated recording area on the disk or a non-volatile memory such as a flash memory.

The spare band is a user data area having the same capacity as the user band, although it is distinguished from a band which is a normal user data area on the disk (hereinafter, sometimes referred to as a user band). The spare band can be transferred to the user band by assigning a logical address (LBA). That is, when valid user data is recorded in the spare band and the LBA is assigned, the spare band is transferred to the user band. On the other hand, among other user bands, a band to which no LBA is assigned is managed as a spare band.

Japanese Patent No. 4886877

In particular, when processing a write command for writing continuous data from the host, a part of the continuous data is written to the spare band, and another LBA data is written to the media cache so that the rewrite process can be performed. Efficiency can be improved. Continuous data is write data in which logical addresses (LBA) are sequentially consecutive.

However, until a new spare band is secured, data is written to the media cache, so the load on the media cache inevitably increases. For this reason, when the free space of the media cache decreases, a delay occurs in the response time of the subsequent write command, which causes a reduction in the efficiency of the rewriting process.

Accordingly, an object of the present invention is to provide a disk storage device and method capable of improving the processing efficiency when rewriting continuous data.

In an embodiment, data is recorded using a head and a recording method in which the head is used to record data in a track area, and the head is used to record data in a track area that partially overlaps the track area. A first area to be recorded, and a space that is radially spaced from the first area, and has a capacity larger than the capacity of the first area, and the data recorded in the first area In response to receiving a disk including a second area for caching, a first write command including continuous first address information and first data relating to the first write command, A first control for recording the first data in the second area; a plurality of second write commands including a plurality of second address information different from the first address information and not continuous; A second control for recording the plurality of second data in the second area in response to receiving a plurality of second data relating to a plurality of second write commands; and the first address. A third write command different from the information and the second address information and including a third address information that is subsequent to the first address information and is continuous, and a third write command. A controller that executes at least a third control for recording the third data in the first area in response to receiving the data.

The block diagram which shows the structure of the disk drive regarding embodiment. The figure for demonstrating the single drite operation | movement regarding embodiment. The figure for demonstrating the structure of the user band and spare band regarding embodiment. The figure for demonstrating the 1st sequential write operation regarding embodiment. The figure for demonstrating the 2nd sequential write operation regarding embodiment. The figure for demonstrating the 3rd sequential write operation regarding embodiment. 6 is a flowchart for explaining a sequential write operation according to the embodiment.

Embodiments will be described below with reference to the drawings.

[Disk Drive Configuration]
FIG. 1 is a block diagram showing a main part of a disk drive according to the present embodiment.

As shown in FIG. 1, the disk drive is roughly divided into a head-disk assembly (HDA), a head amplifier integrated circuit (hereinafter referred to as a head amplifier IC) 11, and a one-chip integrated circuit. And the controller 15.

The HDA includes a disk 1 that is a recording medium, a spindle motor (SPM) 2, an arm 3 on which a head 10 is mounted, and a voice coil motor (VCM) 4. The disk 1 is rotated by a spindle motor 2. The arm 3 and the VCM 4 constitute an actuator. The actuator controls the movement of the head 10 mounted on the arm 3 to a designated position on the disk 1 by driving the VCM 4.

The head 10 has a slider as a main body and a write head 10W and a read head 10R mounted on the slider. The read head 10 </ b> R reads data recorded on the data track on the disk 1. The write head 10R writes data on the disk 1.

The head amplifier IC 11 has a read amplifier and a write driver. The read amplifier amplifies the read signal read by the read head 10 </ b> R and transmits it to the read / write (R / W) channel 12. On the other hand, the write driver transmits a write current corresponding to the write data output from the R / W channel 12 to the write head 10W.

The controller 15 includes an R / W channel 12, a hard disk controller (HDC) 13, and a microprocessor (MPU) 14. The R / W channel 12 includes a read channel 12R that executes signal processing of read data and a write channel 12W that executes signal processing of write data.

The HDC 13 controls data transfer between the host 19 and the R / W channel 12. The HDC 13 controls the buffer memory (DRAM) 16 and executes data transfer control by temporarily storing read data and write data in the buffer memory 16.

The MPU 14 is a main controller of the disk drive, and controls the VCM 4 via the driver IC 18 to execute servo control for positioning the head 10. Furthermore, the MPU 14 controls the head 10 to execute a single write operation as will be described later.

Here, in this embodiment, a cache area called a media cache is secured on the disk 1 on the outer peripheral side, for example. This cache area may be secured in the inner or inner peripheral area of the disk 1 or in a flash memory 17.

[Single drite method]
FIG. 2 is a diagram for explaining a single dwrite operation employed in the disk drive of this embodiment.

In the disk drive, tracks (data tracks) are formed in the radial direction on the disk 1 by writing data on the disk 1 by the write head 10W. As shown in FIG. 2, in the single write method, each track 100 is overwritten sequentially. Such a data recording area (or data capacity unit) including a plurality of tracks (for example, 5 tracks) is called a band (Band0, Band1) 200. Here, in distinction from a spare band 210 described later, a band to which a logical address (LBA) is assigned and normal user data is recorded is referred to as a user band 200.

A guard track is arranged between each band 200 (Band0, Band1) in order to avoid data interference. Here, the data in each band 200 is written in the order of track numbers Track0, Track1, Track2, Track3, and Track4. Each track 100 of track numbers Track 0 to Track 3 is interfered on one side from the track to be written next, and the data signal width becomes narrow. On the other hand, for track 100 with track number Track4, no data is written in the guard track, so there is almost no interference from other tracks.

With such a single write method that performs sequential overwriting, the track interval can be designed to be narrow, so that it is possible to increase the recording density of the data tracks formed on the disk 1.

Here, on the disk 1, the track group configured in the radial direction is divided into a plurality of zones 300 and managed. As shown in FIG. 3, in the present embodiment, the aforementioned spare band 210 is provided for each zone 300 (Zone N and N are numbers). The spare band 210 is distinguished from the user bands 200-0 to 200-4 (Band0-Band4) and is used as a direct writing area without a media cache during a sequential write operation, as will be described later. This is a preliminary recording area.

[Sequential write operation]
Next, the rewriting process by the sequential write operation of this embodiment will be described with reference to the flowcharts of FIGS.

First, the MPU 14 determines whether or not the requested write operation is a sequential write based on a write command (including the logical address LBA) from the host 19 (block 700). Sequential write is an operation of continuously writing (rewriting) continuous LBA data. This embodiment is applied particularly when a plurality of files are sequentially written.

If the write command from the host 19 is not a sequential write but a normal write, the MPU 14 writes the write request data to the media cache (400 described later) on the disk 1 via the buffer memory 16 (block 700). NO, 705). The media cache is an area for temporarily storing data requested to be written by the host 19 when writing data by single write. The media cache is a recording area secured on the outermost peripheral side on the disk 1, for example, and has a capacity sufficiently larger than the capacity of one band. The MPU 14 rewrites data temporarily stored in the media cache by moving it to a band which is a user data area at a predetermined timing.

On the other hand, if the write command from the host 19 is a sequential write (YES in block 700) and the spare band 210 is usable (YES in block 701), the MPU 14 stores the data of the first file. 190A is written into the spare band in the zone corresponding to the LBA to be rewritten (block 702). That is, as shown in FIG. 4, when the spare band 210 is usable, the MPU 14 sequentially writes the data 190A of the first file (for example, LBA starts from 0xF000) (YES in block 701, 702). .

Further, as shown in FIG. 4, when the MPU 14 continuously writes the data 190B of the second file (for example, LBA is 0x1000 to 0x1FFF) by a new write command from the host 19, the spare band 210 has already been set. Since it is used, the data 190B is written to other than the spare band 210 (NO in block 701). For convenience, as a first sequential write operation, the MPU 14 sequentially writes the data 190B to the media cache 400 when a condition described later is satisfied (NO in block 703, NO in 704, 705).

Here, as shown in FIG. 4, when data is sequentially written to the media cache 400, user data of the user band 200-1 (Band1) corresponding to the LBA (0x1000 to 0x1FFF) of the data 190B (that is, Data to be rewritten) becomes invalidation data. In this case, the MPU 14 rewrites the data 190B of the LBA (0x1000 to 0x1FFF) temporarily stored in the media cache 400 by moving to the user band at a predetermined timing. The user band 200-1 (Band1) in which such invalidation data is recorded is referred to as an invalid band for convenience. In other words, the invalid band is an area that can become a new spare band, and is an update recording area in which new data can be recorded.

Next, with reference to FIG. 5, the rewrite operation by the second sequential write operation will be described for convenience.

That is, as shown in FIG. 5, when the MPU 14 continuously writes subsequent data 190C (for example, LBA starts from 0x2000) 190C in the media cache 400 as a recording area other than the spare band 210. Without being written to the invalid band 200-1 (Band1) sequentially (NO in block 701, NO in 703, 7O7).

Here, as shown in FIG. 4, since the media cache 400 contains all user data of LBAs (LBA 0x1000 to 0x1FFF) allocated to the user band 200-1 (Band1), the MPU 14 200-1 (Band1) is set as an invalid band (YES in block 704, 706). Specifically, the MPU 14 sets a flag in table information for managing the user bands 200-0 to 200-n, and sets the user band 200-1 (Band1) as an invalid band.

As shown in FIG. 5, the MPU 14 starts writing data 190C to the user band 200-1 (Band1) set as an invalid band (block 707), and data for one band (LBA is 0x2000 to 0x2FFF). Is continued until the writing is completed (YES in block 703, NO in 708, 709). When the writing of the data 190C to the set invalid band is completed, the MPU 14 assigns an address (LBA) to the user band 200-1 (Band1) (YES in block 709, 710).

After this, the MPU 14 executes a switching process for canceling the invalid band setting for the user band 200-1 (Band1) (block 711). Here, as shown in FIG. 6, when data is sequentially written to the user band 200-1 (Band1), the user data (data to be rewritten) corresponding to the LBA (0x2000 to 0x2FFF) of the data 190C is invalid. It becomes data. That is, the user data recorded in the user band 200-2 (Band2) is invalid data. Therefore, the MPU 14 sets the user band 200-2 (Band2) as an invalid band (YES in block 704, 706).

Next, with reference to FIG. 6, the rewrite operation by the third sequential write operation will be described for convenience.

That is, as shown in FIG. 6, when the MPU 14 continuously writes the subsequent data 190D of the second file, the MPU 14 uses the invalid band 200-2 (Band2) instead of the media cache 400 as a recording area other than the spare band 210. ) Sequentially (NO in block 701, NO in 703, 7O7).

Similarly, the MPU 14 starts writing data 190D to the user band 200-2 (Band2) set as an invalid band (block 707) and continues until the writing of data for one band is completed (block 703). NO, 708, NO of 709). When the MPU 14 finishes writing the data 190D to the set invalid band, the MPU 14 assigns an address to the user band 200-2 (Band2) (YES in block 709, 710).

As described above, according to the present embodiment, the user band 200-0 set as an invalid band instead of being written in the media cache 400, particularly when a plurality of files are sequentially written sequentially by the single write method. Write to ~ 200-n. Therefore, the use of the media cache 400 can be saved. For this reason, even when the free space of the media cache 400 is reduced, it is possible to avoid a situation in which a delay occurs in the response time of the subsequent write command and the efficiency of the rewriting process decreases.

Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Disk, 2 ... Spindle motor (SPM), 3 ... Arm, 4 ... Voice coil motor (VCM), 10 ... Head, 11 ... Head amplifier integrated circuit, 12 ... Read / write (R / W) channel, 13 ... Hard disk controller (HDC), 14 ... Microprocessor (MPU), 15 ... Controller, 16 ... Buffer memory (DRAM), 17 ... Flash memory, 18 ... Driver IC, 19 ... Host, 100 ... Track, 200 ... User band, 210 ... spare band, 400 ... media cash.

Claims (1)

First, data is recorded using a recording method in which data is recorded in a track area using the head, and data is recorded in a track area that partially overlaps the track area using the head. A second area for caching the data recorded in the first area, the area being spaced apart from the first area in the radial direction and having a capacity larger than the capacity of the first area; A disk including:
In response to receiving the first write command including the continuous first address information and the first data relating to the first write command, the first data is recorded in the second area. A plurality of second write commands including a plurality of second address information different from the first address information and different from the first address information, and a plurality of second data relating to the plurality of second write commands. In response to reception, the second control records the plurality of second data in the second area, and differs from the first address information and the second address information, and the first address In response to receiving a third write command that is an address later than the information and includes continuous third address information and the third data related to the third write command, A controller performing at least a third and a control of recording the third data to the first region, and
A disk recording apparatus comprising:

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