JPH03102418A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To attain the reassignment of sectors for improvement of the performance of a magnetic disk device by providing a mechanism which holds the access frequency for each access pattern and a mechanism which secures the correspondence between the logical and physical sector numbers. CONSTITUTION:When the sectors are reassigned, the logical sector numbers forming an access pattern to which the sectors must be reassigned are successively inputted to an address register 10. Then a reading number 122 is given to a RAM 14 every time an access pattern is set to an address register 13. Thus the total access frequency can be read to the access pattern which is required when the sectors are reassigned in a host. Based on the reading result, an optimum sector is reassigned via a sector. As a result, the performance of a magnetic disk device is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a magnetic disk device used in an information processing system or the like.

(Prior Art) Recently, magnetic disk devices and magnetic I-RAM devices have been widely used as external storage devices for computers and the like. Due to the structure of this type of memory arrangement, it is difficult to reduce the access time below the millisecond unit, and its performance is largely dependent on the access time.

The access tie l1 of a magnetic disk drive device is the one hour it takes for the head 11 to move between cylinders, the time it takes after the movement, the wait time for the disk to rotate simultaneously, and the time it takes for the head to stabilize after it makes contact with the disk. Contains. In this, the disk rotation i1g waiting time is the waiting time until the logical sector number passes through the sector specified by the logical sector number or the head when the head I is on the cylinder. The rotation waiting time occupies a large proportion of the time.

(Problem to be Solved by the Invention) However, in the prior art, following the sector currently being accessed in the same cylinder 7 on a disk rotating in the right direction, physical attachment is performed on the sector. Even if there are many patterns of accessing the sector on the right, the problem is that access cannot be made until the disk rotates once each time. - As a method to solve the problem described in L, there is a method of reallocating sectors and moving the sector on the right to the sector on the left, thereby reducing the disk rotation waiting time when accessing this pattern next time.

The present invention solves the above conventional problems, and sets physical sector numbers corresponding to logical sector numbers used when reallocating sectors, and The object of the present invention is to provide a magnetic disk device that automatically counts the number of accesses to a pattern.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a magnetic disk device with means for storing physical sector numbers in storage devices designated by logical sector numbers, and means for generating one address using two physical sector numbers corresponding to the logical sector number of the sector being accessed and the logical sector number of the sector that was accessed immediately; The method comprises means for adding 1 to the number of accesses for a pattern of continuously accessed sectors read from a designated storage location, and then storing the addition result in the storage location.

(Function) Therefore, with the above configuration, the present invention makes it possible to provide the same total number of accesses and the physical sector number of sectors for patterns of consecutively accessed sectors. By reallocating sectors, the performance of the magnetic disk device can be improved.

(Embodiment) The upper figure shows the principle of sector reallocation. Assume that during formatting, sectors are written in the order shown in FIG. 1(a). If the pattern of accessing in the order of A-+B occurs frequently during reading, the pattern shown in Fig. 1 (b
) by reallocating sectors as shown in
Next, it becomes possible to significantly reduce the rotational waiting time when accessing in the three patterns of order A-)B.

FIG. 2 shows the configuration of a magnetic disk device in one practical example of the present invention. In FIG. 2, 10 is an address register, and 11 is a RAM that stores physical sector numbers.
, 12 is a launch circuit (a) that stores a pair of physical sector numbers indicating a pattern of consecutively accessed sectors.
, (b), 13 is an address register, 14 is a RAM that stores the total number of accesses of the pattern, {5 is an adder, 111 to H8 are sector numbers, 1.20 latches the contents of the latch circuit 12(a) Signal transferred to circuit 12(b), 12↑ is RAM]. Write signal for writing to 4, 1
22 is RAM. a read signal for reading from 14, 12
3 is the total number of accesses, and 131 to 135 are physical sector numbers.

Next, the operation of the above embodiment will be explained. In the above embodiment, when logical sector numbers 111 to 118 are given from the host, the R A specified by the address register 10 is
From the storage location of Mll, physical sector numbers 131 to 135 corresponding to the above logical sector numbers are stored in the latch circuit 1.2(a). At the same time, a signal 120 is applied to the latch circuit 12, and the latch circuit 12(a)
The physical sector number of the most recently accessed sector stored in latch circuit 1.2(b) is stored in latch circuit 1.2(b).

On the other hand, the output 124 of the latch circuit 12(a) is input to the upper bit part of the address register 13, and the output 125 of the latch circuit 12(b) is input to the lower bit 1~ part of the address register 13. This set of physical sector numbers of continuously accessed sectors is an access pattern, and the total number of accesses 123 for the access pattern is output from the storage location of the RAM 14 specified by the access pattern set in the address register 13. Ru. The total number of accesses 123 becomes one input of the adder 15. Since the other input of the adder 15 is pulled up, the output 126 from the adder 15 is the total number of accesses 123 plus 1. here,
RAM. When the write signal 121 is applied to adder l5
The output 126 from the address register 13 is stored in the storage location specified by the address register 13. Through the above operations, all the access counts for the access pattern between sectors in the same cylinder can be stored in the RAM 1.4.

Next, when reallocating sectors, sequentially enter logical sector numbers in the address register 10 that give access patterns that are considered necessary for sector reallocation, and set the access pattern in the address register 13. By applying a read signal 122 to the RAM 14 each time a host performs sector reallocation, it is possible to read the total number of accesses for the access pattern required when the host reallocates sectors.

Using this result, optimal sector reallocation is performed in sectors.

(Effects of the Invention) As is clear from the above-mentioned actual examples, the present invention realizes a mechanism for retaining the number of accesses for each access pattern and a mechanism for associating logical sector numbers with physical sector numbers in a magnetic disk device. This has the effect of making it possible to reallocate sectors to improve the performance of the magnetic disk device.

[Brief explanation of drawings]

Figure 1 is a diagram to explain the effect of re-anatomizing the sector.
FIG. 2 is a diagram showing the configuration of a magnetic disk device in one practical example of the present invention. 10. 13 ・Address register, 1.1.14・
・RAM, 12...Latch circuit, 15...Adder.

Claims (1)

[Claims] means for storing a physical sector number in a storage location designated by the logical sector number; and a set corresponding to the logical sector number of the currently accessed sector and the logical sector number of the sector that was accessed immediately before. means for generating an address using a physical sector number of the address, and adding 1 to the total number of accesses for the pattern of subsequently accessed sectors read from the storage location specified by the address, and then adding the result to the storage location; A magnetic disk device comprising means for storing.