JPH10105445A - Storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage device for improving a response time. SOLUTION: CPU 11 reads the file name, the file size and the leading cluster number of a file information area in the format of a disk device 20, refers to access information at every file recorded in an access information area, executes arrangement in order of access times in the respective file so as to generate a file updating order map and permits RAM 13 to store it. Then, the arrangement order of file information in the file information area is changed. That is, the file with more access times is arranged in the higher part of the updating order map.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a storage device having a physical drive using a disk as a storage medium and a controller for controlling the operation of the physical drive.

[0002]

2. Description of the Related Art Conventionally, there is known a storage device including a physical drive using a disk as a storage medium and a controller for controlling a plurality of physical drives by, for example, one logical drive. As an example, by providing a controller for controlling a plurality of disk devices as one logical drive, an apparent (one) disk device responds to a request from the outside (for example, a host computer). There is a disk array device. In addition, there has been proposed a system in which a file management unit is provided in a controller to perform file management on a file basis. Such a disk array device has been used in, for example, a video server or the like by utilizing its large capacity and high speed.

[0003]

In general, file management including file names, file attributes, file sizes, leading cluster numbers, and the like is required to manage files on a file-by-file basis. It was recorded on the table. When a file is created or deleted, the file information table is updated, but the arrangement of each file information is almost fixed.

However, if such a file information table is used, it may take time to search for the file information depending on the position in the table (ie, the recording position on the disk). Then, since it takes time to respond to the access request, there is a problem when the disk array device is incorporated in a system requiring high-speed access such as a video server. In particular, this problem was remarkable when the file information of a frequently accessed file was located at a position where such a search took a long time.

[0005] The present invention has been made to solve the above-mentioned problems, and has as its object to improve the response time of a storage device using a disk.

[0006]

According to a first aspect of the present invention, there is provided a storage apparatus comprising: a physical drive that uses a disk as a storage medium; and a file stored in the physical drive. A storage device comprising: a controller having a file management unit that manages files in file units using the file information, wherein an access record unit that records an external access history in file units; and File information arrangement means for dynamically relocating the arrangement of each file information in the file information storage area.

In the storage device according to the present invention, the controller comprises:
The operation of a physical drive using a disk as a storage medium is controlled. A hard disk device is known as such a physical drive. Also, as a disc,
Floppy disk, magneto-optical disk (MO), CD-
Although R and the like are exemplified, any rewritable disc can be used in the present invention.

In this storage device, since the file management means of the controller manages the files stored in the physical drive in file units, an external access request only needs to specify the file. Further, there are provided access recording means for recording an access history from the outside in file units, and file information arrangement means for dynamically relocating the arrangement of each file information in the file information storage area based on the access history. Therefore, the file information of the frequently accessed file can be relocated to a position where the search does not take much time, and the file information of the less frequently accessed file can be rearranged to a lower position. An example of the position where the search does not take much time is on the side close to the boot sector area, and on the disk, it can be said that it is near the outer periphery.

[0009] Thus, it does not take much time to search for the file information of the frequently accessed file. Therefore, the response time of a frequently accessed file is improved. On the other hand, it can be said that the response time of a file with a low access frequency is reduced, but as a whole, the improvement of the response time by placing the file information of the file with a high access frequency at the top is superior. Therefore, the response time of the storage device is improved as a whole.

The storage device according to claim 2 is the storage device according to claim 1, wherein the controller relocates the file in the physical drive in response to the relocation of the file information. It is characterized by comprising means.

As described above, the response time of the storage device can be improved only by dynamically relocating the file information. However, a file which is accessed more frequently can be placed in a location which does not require a long time to read, for example, a sequential file. With such an arrangement capable of performing an accurate reading, the effect of the configuration of claim 1 is further improved.

According to a third aspect of the present invention, in the storage device according to the first or second aspect, the physical drive forms a physical drive array with a plurality of the physical drives, and the controller comprises:
The physical drive array is controlled as one logical drive.

This storage device apparently responds to an external access request as if it were a single physical drive. In this storage device, for example, when striping such as RAID4 is adopted, a physical block of another physical drive is sought during data transfer from a physical block of one physical drive, and a prefetch to a cache is performed. Therefore, very high-speed data reading can be performed as a whole. Therefore, the effect of claim 1 or 2 is further improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings to explain the embodiments of the present invention. (Embodiment) FIG. 1 is a block diagram showing a schematic configuration of a file server including a disk array device 1 as a storage device of the present embodiment. This file server is composed of a disk array device 1 and an external computer 30 for giving instructions to the disk array device 1 for reading and writing data, and both are connected via a bus 25.

Data is input from the outside to the disk array device 1 via the bus 25, or the disk array device 1
Can output data to the outside via the bus 25. Specifically, for example, MP as data input means
The compressed video data from the EG encoder 40 is input, or, for example, MPEG data is output to the terminal 50, and is decoded as a video signal in the MPEG decoder of the terminal 50. The external computer 30 can acquire a video data transmission request from the terminal 50, and can instruct which file (video data) to output to the disk array device 1 based on the video data transmission request. .

The disk array device 1 includes a plurality of disk devices (HDs) for storing a large amount of video data which can be supplied as a disk controller 10 and a video server.
D) 20). Disk controller 10
Is a CP serving as control means for the entire disk array device 1.
It is configured around U11. This CPU 11
Function as a file management means, a file information arranging means, and a file rearranging means of the present invention. The disk controller 10 includes a ROM 12 serving as a program storage unit that stores an operation program of the CPU 11 such as array management software,
A RAM 13 serving as a work area of U11, an interface device 14 connected to a bus 25 for taking an interface with the outside, a cache memory 15, a protocol control device 17, and the like are provided.

The cache memory 15 has a disk device 2
It operates as a disk cache for data output from 0 to the outside and data input to the disk device 20 from the outside. Further, the protocol control device 17 performs data transfer between the disk device 20 and the cache memory 15.

In FIG. 1, one protocol control device 17 is connected to the cache memory 15, and each protocol control device 17 has three protocol control devices 17.
Although one disk device 20 is connected, the number of protocol controllers 17 connected to one cache memory 15 and the number of disk devices 20 connected to one protocol controller 17 are increased or decreased as necessary. it can. Also,
The disk device 20 is a device in which a so-called physical disk drive unit and a control unit for controlling the same are integrated.

The CPU 11 of the disk controller 10
Is based on array management software or the like in the ROM 12 and is connected to each disk device 2 via the protocol controller 17.
0 can be operated simultaneously in parallel. The disk format structure of the disk device 20 in the disk array device 1 is as shown in FIG.

First, a boot sector area 110 is secured at the highest position of the address, then a file allocation area (FAT) 120, and then an access information area 13
0, the file information area 140, and the data recording area 150 are set in this order.

The boot sector area 110 is no different from that in a known disk device. Also, the file allocation area is the same as that of the well-known one. For example, in a disk operating system often used for a personal computer, the disk device 2
0 and a FAT-ID for identifying the file allocation area 120 itself.
Then, cluster information # 1 to #N are recorded.

The access information area 130 is unique to the present invention.
Functions as access recording means. In the access information area 130, information as a pair of the file ID of each file and the number of access requests to each file, that is, the number of accesses, is recorded as access information for each file recorded on the disk device 20. .

In the file information area 140, a file name, a file attribute, an access time and date, a file size, a leading cluster number, and the like are recorded as file information in units of each file recorded on the disk device 20. The disk controller 10 can manage each file on a file-by-file basis by using the file information.

The data recording area 150 is an area for recording files. Usually, one file is divided into a plurality of clusters and recorded, and a plurality of such files are recorded. In the disk array device 1, the arrangement of each file information in the file information area 140 and the arrangement of each file in the data recording area 150 are not fixed but may be changed as appropriate. Next, a change in the arrangement will be described.

FIG. 3 shows the disk controller 10 when it is not necessary to perform the function as a file server, for example, when there is no access request from the external computer 30.
9 is a flowchart of a file information update process executed by the CPU 11 of FIG. As shown in FIG.
Reads the file name, the file size, and the leading cluster number from each file information in the file information area 140 and sets it as execution file information. The execution file information is used as the access information for each file recorded in the access information area 130. Referring to FIG. 4, a file update order map (see FIG. 4) is generated by arranging the files in the order of the number of accesses to each file, and is stored in the RAM 13 (step 100,
Hereinafter, the step is abbreviated as S).

Next, the CPU 11 changes the arrangement order of the file information in the file information area 140 with reference to the update order map. The processing related to the rearrangement will be described with reference to FIG. In FIG. 5, the number of files is set to 5 (file 1 to file 5) to simplify the description without losing the essence of the invention.

As shown in FIG. 5, prior to the processing, the file information of the file 1 is placed at the top and the file information of the file 5 is placed at the bottom in the file information area 140. . The number of accesses is file 3 (150 times), file 4 (100 times), file 2 (50 times), file 1 (25 times), file 5 (1
0 times). Therefore, the order in the above-mentioned file update order map is the order of file 3, file 4, file 2, file 1, and file 5.

Then, the CPU 11 rearranges the order of each file information in the file information area 140 according to this order. Then, as shown in FIG. 5 after the processing, the file information of the file 3 is at the top,
The arrangement is such that the file information of the file 5 is at the bottom.
As shown in FIG. 2, that the arrangement in the area is higher is that the data is recorded on the side closer to the boot sector area 110 (closer to the outer circumference on the disk). For example, when the disk device 20 in the idle state reads the file information, the head moves less in the file information higher in the file information area 140 and less seek time is required. The time required will be small. Therefore, by arranging the file information of the frequently accessed file at the upper position in the file information area 140, the search of the file information of the frequently accessed file does not take much time. Time improves. On the other hand, it can be said that the response time of a file with a low access frequency is reduced, but as a whole, the improvement of the response time by placing the file information of the file with a high access frequency at the top is superior. Therefore, the response time of the disk array device 1 is improved as a whole.

As shown in FIG. 3, following the rearrangement of the file information (S200), the CPU 11 extracts one piece of file information from the file information area 140 (S30).
0), based on the file information and the update order map, a file reconstructing (fragmentation) process is performed so that the reading process of the file corresponding to the file information can be optimized (S400). In the present embodiment, processing is performed so that this file is arranged in a continuous area in the data recording area 150, and the position in the data recording area 150 is the order position in the update order map.

Then, data for one file is allocated to a continuous cluster, and the higher the rank in the update order map (the larger the number of accesses), the higher the rank in the data recording area 150. For this reason,
When the reading process of file data is executed,
Since the seek time of the head when moving from one cluster to the next cluster is the shortest, reading can be performed quickly.
Also, since the higher the number of accesses to a file, the higher the number of accesses, the higher the number of accesses to the file, the shorter the time required for seeking the first cluster of the file.

Next, the CPU 11 updates the file information by reflecting the result of the fragmentation (such as a change in the leading cluster number) (S500). Subsequently, fragmentation is performed on all the files (S40).
0) and whether or not the file information has been updated (S500) (S600). If any of these files has not been processed (S600: NO), S30 is executed.
0, the next file information is extracted, and S400-S
Step 600 is executed. Hereinafter, similarly, S300-
S600 is repeated, and if these processes (S300 to S500) have been executed for all the files (S600
600: YES), and ends the file information updating process.

As described above, in the disk array device 1 of the present embodiment, the order of each file information in the file information area 140 is rearranged and rearranged in the descending order of the number of accesses. Is recorded on the side closer to the boot sector area 110 (closer to the outer periphery on the disk). Boot sector area 1
If the value is close to 10, the seek time for reading is short, so that the file information of a file with a large number of accesses requires less time for the access.

By arranging the file information of a file with a high access count at a higher position in the file information area 140, it does not take much time to search for the file information of a file with a high access frequency. Response time improves. On the other hand, it can be said that the response time of a file with a low access frequency is reduced, but as a whole, the improvement of the response time by placing the file information of the file with a high access frequency at the top is superior. Therefore, the response time of the disk array device 1 is improved.

Moreover, since each file is arranged in a continuous area in the disk device 20 by the fragmentation, the reading of the file data becomes sequential, and the seek time of the head when moving from one cluster to the next cluster is taken. Since it is the shortest, reading can be performed quickly. Also, since the higher the number of accesses to a file, the higher the number of accesses, the greater the number of accesses, the shorter the time required for seeking the first cluster of the file.

Although the embodiments of the present invention have been described above with reference to the embodiments, the present invention is not limited to such embodiments at all, and various forms may be provided without departing from the gist of the present invention. Can be implemented. For example, in the embodiment, the access information area for recording the access history from the outside in a file unit is provided in the disk device, but it may be provided in the controller side (for example, RAM).

[0036]

As described above, in the storage device according to the first aspect, by dynamically rearranging the file information, the time required for searching for the file information of the frequently accessed file can be shortened. The response time has improved.

According to the storage device of the second aspect, since the files can be arranged so that reading does not take a long time, the effect of the configuration of the first aspect is further improved. In the storage device according to the third aspect, by operating a plurality of physical drives in parallel, for example, during data transfer from a physical block of a certain physical drive, a physical block of another physical drive is sought, and furthermore, the data is transferred to a cache. Can be read in advance, so that very high-speed data reading can be performed as a whole. Therefore, the effect of claim 1 or 2 is further improved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a file server including a disk array device according to an embodiment.

FIG. 2 is an explanatory diagram of a disk format in the disk array device of the embodiment.

FIG. 3 is a flowchart of a file information update process executed by a CPU of the disk device of the embodiment.

FIG. 4 is an explanatory diagram of a file update order map constructed by a CPU in a file information update process.

FIG. 5 is an explanatory diagram of relocation of file information in a file information update process.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Disk array apparatus, 10 ... Disk controller, 11 ... CPU (File management means, File information arrangement means, File rearrangement means), 12 ...
ROM, 13 RAM, 14 interface device, 15 cache memory, 17 protocol control device, 20 disk device (physical drive, access recording means), 25 bus , 30 ...
External computer, 40 ... MPEG encoder, 5
0 ... terminal.

Claims (3)

[Claims] 1. A storage device comprising: a physical drive using a disk as a storage medium; and a controller having file management means for managing files stored in the physical drive on a file-by-file basis using file information of each file. An apparatus, comprising: access recording means for recording an external access history in file units; file information for dynamically relocating the file information in a file information storage area based on the access history. A storage device comprising an arrangement unit. 2. The storage device according to claim 1, wherein the controller includes a file relocation unit that relocates the file in the physical drive in response to the relocation of the file information. Storage device. 3. The storage device according to claim 1, wherein a plurality of said physical drives constitute a physical drive array, and said controller controls said physical drive array as one logical drive. Storage device.