JP5039463B2 - Recording apparatus and recording method - Google Patents

Description

  The present invention relates to a recording apparatus.

  In recent years, hard disks with a large capacity have been installed not only in servers and personal computers but also in various devices such as recording devices (hard disk recorders), car navigation systems, and audio components. A hard disk drive (HDD) reads and writes data using a magnetic head on a magnetic body on a high-speed rotating disk, but it has many mechanically driven parts, and has a failure compared to non-volatile semiconductor memory (flash memory, etc.). Many devices. In order to reduce the failure rate, measures are mainly taken from the viewpoint of improving the durability of hardware.

On the other hand, the failure rate varies depending on how the HDD is used. For example, when data is written to the HDD, erased immediately after that, and the same size data is written next, the next writing is usually performed in the same area. If this operation is repeated, the same area of the HDD will be used repeatedly, increasing the failure rate. Similarly, if the number of accesses in a specific use area is high, the failure rate increases.
When recording video on the HDD, it is usually stored in a continuous area. This is because reading / writing is faster in the continuous area.

  On the other hand, in recent years, a large amount of information (content metadata) relating to content such as video may be accumulated. Such metadata is usually about several kilobytes in size, and is stored in a file system suitable for random access that can be read quickly.

  In other words, video and metadata should be stored in different areas and different file systems for performance reasons. At this time, for example, 100 metadata of 10 Kbytes is 1 Mbyte, but video data of 24 Mbps is 5 Gbytes or more in one event for 0.5 hour. Then, the size ratio between the video area and the metadata area is 1000 times or more, and access is biased to some areas.

  As a measure for reducing the failure rate against repeated use in such a biased area, several methods for leveling the bias in the number of accesses to the same disk area have been proposed.

  In Patent Document 1, the number of accesses to the HDD per file is recorded, and a file with a large number of accesses is moved to a disk area with few accesses. In Patent Document 2, the number of data accesses is recorded in units of areas, and the next area to be written is written to an area with a small number of accesses. . In Patent Document 3, a temporary data storage area that is frequently used is used in combination with a long-term storage area to try to level access to the HDD.

JP 7-64828 A JP 2000-172538 A However, in the measurement method using the number of accesses to a file or area, the measurement cost increases in proportion to the increase in the number of files or areas. For example, in recent years, HDD capacity of over 1 terabyte has appeared. In a digital broadcast program, about 30 gigabytes are consumed for one 30-minute program, and about 200 programs can be recorded on one HDD. However, so-called metadata such as program information is usually several kilobytes at most. When handling data such as metadata that does not involve video, the number that can be recorded on a single HDD increases dramatically. This becomes a problem that the cost of measuring the number of accesses increases.

  As for the number of accesses to an area, the use efficiency of the area deteriorates when the area is divided largely, and the measurement cost of the access number of the area increases when the area is divided finely. There is also an essential problem with the method of measuring the number of accesses to a file. For example, even when the access to a specific area on the HDD is remarkably increased, the physical access to the magnetic recording portion of the HDD does not occur when the cache on the HDD is hit. The number of accesses can be easily measured by a device that uses an HDD. However, considering the cache of the HDD, the number of accesses needs to be incorporated into the HDD device itself.

  For this reason, it becomes a problem to equalize the number of accesses to the HDD by reducing the cost of measuring the number of accesses or calculating the data to be moved and the destination area without using the number of accesses.

  This problem can also be applied to flash memory. A flash memory is a semiconductor and has no mechanical drive part, but has a limited number of times of writing. In other words, if access to the same area is concentrated, a failure occurs. Therefore, leveling the number of accesses to the memory becomes an issue.

  The problem to be solved is to level the number of accesses in a simple manner in a recording device such as an HDD.

  The main feature of the present invention is that the number of accesses is leveled by dividing the recording medium into an area having a high access frequency and an area other than that and periodically moving the area having a high access frequency to another area. And

  The recording apparatus of the present invention has the effect of reducing the possibility of failure due to the uneven number of accesses to a specific area because the number of accesses to the area is leveled.

By setting a high access area on the recording medium in advance and moving the random access area to another area periodically or when a threshold is exceeded, the number of uses on the medium is leveled. The purpose of lowering the failure rate was realized with a simple configuration.

  FIG. 1 is an overall view of a device of the present invention in Example 1. Reference numeral 100 denotes a device that uses an HDD, such as an HDD recorder, a personal computer, or an HDD car navigation system. Reference numeral 101 denotes a leveling LBA (Logical Block Addressing) management unit, which mainly manages the sector number of the high access area, which is a feature of the present invention. LBA is a method of managing by assigning numbers to sectors.

  In the present invention, sector numbers are assigned in order from the outer periphery, but other methods may be used. Reference numeral 102 denotes a movement control unit that performs control when moving the high access area to another area. Reference numeral 103 denotes functions other than 104 and 105 which the apparatus 100 generally has. An HDD controller 104 controls the HDD 105. Note that 101 and 102 may be implemented by either hardware or software.

  FIG. 2 is an internal configuration diagram of the HDD in the present invention. 200 is an HDD. An actuator 201 controls the magnetic head 202. Reference numeral 203 denotes a bearing, which is the center of rotation of the magnetic disk indicated by 211 to 213. 211 is a high access area. The high access area is an area that is known in advance to have a high frequency and frequency of reading and writing. For example, an area reserved for a database can be used. A moving buffer area 212 is used only when moving in the high access area. Reference numeral 213 denotes another area, which is an area for data other than data to be written in 211, such as video data and music data.

  FIG. 3 is a table for managing the sector numbers of the recording areas 211 to 213 in FIG. The table includes an area 301, a start sector 302, and an end sector 303. For example, the high access area 211 is the record 304 in the table, the start sector number is 1, and the end sector number is 2097152. The movement buffer area 212 corresponds to the record 305. Other area 213 corresponds to record 306. Note that the number of records in this table may be expanded when there are two or more areas.

  FIG. 4 is an internal configuration diagram of the HDD in a state where the movement of the high access area, which is a feature of the present invention, is completed. 400 is the same HDD as 200. The high access area 211 has moved to the area 412. Further, the movement buffer area 212 has moved to the area 413. Note that the data that originally existed in the area 413 has been moved to the area 411 by securing the area 413. A region 414 is another region.

  Next, the basic flow of the present invention for changing the recording area of the HDD from FIG. 2 to FIG. 4 will be described with reference to FIG. Note that this process is started at an initialization process performed in a factory or the like, but may be started by an initialization operation instruction or the like by a user. When the process is started, the disk is formatted and a partition is set (501). The partition includes at least a high access area 211, a movement buffer area 212, and other areas.

  The partition size of the high access area is usually calculated at the time of designing the high access area, and the calculated value is held by the partition creation function existing in 103. In addition, when it is desired to use an area exceeding the partition size once created, a general method for enlarging the partition may be applied. In this case, the sector number related to the changed partition is reflected in the leveling sector number table. It may also be reflected in the file system mapping table. The partition size of the moving buffer area is set to be the partition size of the high access area or larger.

  Next, the high access area is set in the address management unit. The address management unit sets the sector number of the high access area in the leveling sector number table of FIG. 4 described later (502). Next, the movement control unit initializes the movement buffer and sets the sector number of the movement buffer area in the leveling sector number table (503). Thus, the preparation process is completed, and a leveling process start trigger is awaited (504). The start trigger of the leveling process may be periodically activated by a timer that measures the operation time of the HDD.

  Alternatively, the number of accesses to the HDD may be measured, and activation may be performed when the threshold value is exceeded. Alternatively, software or hardware that uses the high access area may be activated by notifying the movement management unit. Moreover, you may start regularly using a calendar and a clock. When the trigger is activated, the movement control unit instructs the HDD controller 104 or other function 103 using the HDD to stop access to the high access area and copies the data in the high access area to the movement buffer 212 (505). .

  Next, the data in the high access area 211 that is the migration source is deleted in 505 (506). Note that step 506 may be omitted if all of the migration source high access area 211 is overwritten in step 507. Next, the movement control unit 102 instructs the HDD controller 104 or the other function 103 using the HDD to stop access to the other area 213 of the recording area, and newly stores the data in the area 413 to be reserved as a movement buffer 505. The file is copied to the high access area 411 that is the movement source (507).

  Note that the size of the area 413 newly reserved as a movement buffer is equal to or larger than the size of the high access area 412. Further, the area secured as the movement buffer is an area that has never been used as a high access area. For example, it is only necessary to always ensure the order from the outer periphery to the inner periphery. When using the innermost circumference, secure the outermost circumference. Next, the start sector number and end sector number of each area after movement are reflected in the leveling sector number table, and the sector numbers used in the other function 103 are reassigned (508).

  This process is a process of changing the mapping to a sector number generally performed by the file system to a new sector number. This mapping change may be explicitly performed by software using the HDD. When step 508 ends, step 502 is executed. In this example, the high access area is secured on the outside and the movement buffer area is secured on the inside, but the reverse is also possible. In this case, the high access area and the movement buffer area are used as opposite positions. The movement buffer area may be secured as a fixed area. In this case, for example, a moving buffer area is provided near the innermost periphery.

  A specific example to which the present invention is applied is an HDD recorder. Other area 213 is allocated as a video area of the HDD recorder. Further, the high access area 211 is allocated as a database area where random access is frequently performed. The movement trigger is activated at AM 1:30 once a month from the first use date. For example, assuming that the capacity of the HDD recorder is 1 terabyte and the database area is 10 gigabytes, the migration process can be performed 100 times. Then, the same high access area will not be used for 8 months or more for 1 month or more, and the failure rate of the HDD will be reduced.

  As described above, according to the present invention, the number of accesses to the HDD can be leveled by a simple method, and the failure rate can be reduced.

  In the second embodiment, the function existing outside the HDD in the first embodiment is taken into the HDD. FIG. 6 is an overall view of the device of the present invention in the second embodiment. 600 is an HDD. Reference numeral 601 denotes a connection interface to the HDD. Reference numeral 602 denotes a sector address conversion unit. The sector address conversion unit has a function of converting a sector address so that a device using this HDD does not have to worry about the change of the sector number accompanying the leveling process. Reference numeral 603 denotes a movement control unit, which has the same function as 102. Reference numeral 604 denotes a controller, which is similar to a general HDD built-in controller. Reference numeral 605 denotes a mechanical part such as an actuator.

  In this embodiment, the basic flow is the same as in FIG. However, the movement trigger is notified to the movement control unit 603 through the interface 601, or the movement control unit starts the trigger using the number of accesses to the HDD and the access time, using a clock or a calendar built in the HDD. A trigger may be activated periodically.

  FIG. 7 shows sector address conversion performed by the sector address conversion unit 602. Reference numeral 700 denotes an area configuration when the HDD is viewed from the interface 601. A high access area 711, a movement buffer area 712, and other areas 713 are formed. Reference numeral 720 denotes an area configuration on an actual disk converted by sector address conversion.

  For example, when the high access area 711 is accessed via the interface 601, the address conversion unit 602 converts it as 741 and accesses the area 722. Similarly, when the other area 713 is accessed, the address conversion unit 602 converts it as 743 and accesses the areas 721 and 724. Note that since the leveling movement process is performed by the HDD, it is not necessary to access the area 712.

  With the configuration as described above, the effect of the present invention can be obtained by a single HDD and a simple movement trigger notification.

  The third embodiment is an example in which the function realized by the HDD in the first embodiment is applied to a flash. FIG. 8 is an overall view of Embodiment 3 of the apparatus of the present invention. 801 to 803 may be realized by either software or hardware. Reference numeral 801 denotes a flash memory access interface. Reference numeral 802 denotes an address conversion unit, which has a mapping table that does not make address conversion conscious as shown in FIG. Reference numeral 803 denotes a movement control unit. A control unit 804 drives the flash memory. Reference numeral 805 denotes a flash memory.

  In this embodiment, the basic flow is the same as in FIG. However, the movement trigger is notified to the movement control unit 803 through the interface 801.

  FIG. 9 is an area configuration diagram on the flash memory. Reference numeral 900 denotes a flash memory 805. Reference numeral 901 denotes a high access area, reference numeral 902 denotes a movement buffer area, and reference numeral 903 denotes other areas. The movement buffer area secured by the movement process 507 is secured from the area 903 immediately below 902.

  Since the flash memory has a limited number of rewrites, a process that does not write to the same area during normal writing is performed. When such processing is performed, high access data is scattered over the entire area of the flash memory. Therefore, in this method, the locations in the memory of the high access area are grouped into 901. A conventional mechanism for preventing writing to the same area in 901 may be used.

  By using this method, high access data is not scattered and random access can be provided at high speed with a simple mechanism. For example, if the area 901 is read out as a large block and placed on the volatile memory, the access becomes faster. Write to flash memory when necessary.

It is a block diagram of this invention apparatus. It is a figure which shows the allocation before the movement of a high access area | region. It is a figure which shows the start sector and end sector of each area | region. It is a figure which shows the allocation of the area | region after the movement of a high access area | region. It is a basic flow of the present invention. It is a block diagram at the time of mounting a sector address conversion part and a movement control part in HDD. It is a figure which shows mapping of a virtual area | region and an actual area | region. It is a block diagram at the time of applying to a flash memory. It is a figure which shows the allocation of the area | region on flash memory.

Explanation of symbols

100 Device using HDD 101 Leveling LBA management unit 102 Migration control unit 103 Other function unit of device using HDD 104 HDD controller 105 HDD

Claims (9)

A recording device having a function of reading and writing data,
Provide a high-access area to record frequently accessed data ,
From a region other than the high access area, and means for securing the area of the same or greater than the size of said high access area,
The data of the high access area, and means for copying to the area secured,
Means for copying data existing in the secured area to the area that was the high access area;
Means for giving a trigger to start copying;
Means for changing an address of the high access area changed by copying,
The means for copying the data in the high access area to the reserved area,
The data in the high access area indicated by the address changed by the means for changing the address is sequentially copied to an area other than the high access area and designated in a predetermined order. A recording apparatus. The recording apparatus according to claim 1,
Provide a buffer area for movement,
Instead of copying the data in the high access area to the reserved area, the data is copied to the migration buffer area, and the data existing in the reserved area is copied to the area that was the high access area. A recording apparatus comprising means for copying data in a movement buffer to the reserved area. 3. The recording apparatus according to claim 1, wherein the means for giving a copy start trigger is a means for giving a trigger every predetermined time. 3. The recording apparatus according to claim 1, wherein the means for giving a copy start trigger is a means for giving a trigger when it is detected that the number of times of reading and writing to the high access area exceeds a set value. There is a recording apparatus. A recording apparatus according to any one of claims 1 to 4, wherein said means for changing the address of the high access area is changed by the copy is to be a means for changing the mapping table of the file system A recording apparatus. 6. The recording apparatus according to claim 1, wherein the copy start trigger is given from an apparatus external to the recording apparatus. The recording apparatus according to claim 1, wherein the recording apparatus is a hard disk drive. The recording apparatus according to claim 1, wherein the recording apparatus is a flash memory. A recording method in a recording apparatus for reading and writing data,
Provide a high-access area to record frequently accessed data,
From an area other than the high access area, ensure an area of the same size or larger than the high access area
The data of the high access area, copy it to the area secured,
Copy the data present in the secured area to the area that was the high access area,
Change the address of the high access area that is changed by copying,
A recording method comprising : sequentially copying the data in the high access area indicated by the changed address to an area other than the high access area and designated in a predetermined order .

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