JPH02304614A - Peripheral equipment access system - Google Patents

Abstract

PURPOSE:To automatically equalize each physical device load and to effectively utilize the whole capacity of the physical device by providing plural address registers, an address conversion table and an address converting circuit. CONSTITUTION:This system is constituted of registers 301 - 303, 307 and 308, an address conversion table 304, and an address converting circuit (divider 305, adder 306). In such constitution, by a processor and a memory 1, a device address and a record address sent from a channel 2 are stored in a logical device address register 301 and a logical device address register 302, respectively. Subsequently, by the divider 305, a value of the register 302 is divided by a value of a physical number of device register 303 and the remainder and the quotient are sent to a physical device address register 308 and the adder 306, respectively. The physical record address derives a head physical record address by using the table 304 from the value of the register 301, adds and calculates this address and the quotient, and stores it in the physical record address regis ter 307.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a load distribution method for peripheral devices in an information processing system, and in particular, to a method for reducing load imbalance of high-speed file devices such as magnetic disk storage devices. Concerning how to avoid and eliminate the need for tuning.

[Prior Art] Conventionally, in order to equalize the load among a plurality of devices, a division organization method has been adopted in which one file is divided and stored in a plurality of devices using software. However, since the access frequency differs significantly from file to file, it takes a great deal of time and effort to allocate files to each physical device in consideration of load equalization during system design.

Furthermore, as a method for solving the problem of device access frequency caused by the increase in the capacity of peripheral devices, there is a method of making one device appear as multiple logical devices.

This method is effective in resolving bottlenecks due to exclusive control on a device-by-device basis, but as the capacity of magnetic disks increases, the lock unit becomes larger, so the traffic limit is determined by exclusive control on a device-by-device basis. The problem is that the magnetic disk storage capacity of the device cannot be used effectively, and the physical device bottleneck itself cannot be resolved.

[Problems to be Solved by the Invention] In order to improve the drawbacks of the conventional peripheral device allocation method as described above, the present invention provides a system that includes a plurality of physical devices such as a magnetic disk storage device.
The purpose of this invention is to provide a method that applies interleaving to one logical device to equalize physical device loads and reduce load imbalance between devices.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a register that stores a logical device address sent from a channel, and a register that stores a logical record address sent as data from the channel. Register, register that stores the number of physical devices stored in the auxiliary storage control unit, conversion table between logical device address and first physical record address, divider to calculate physical device address from logical record address, inside physical device , an adder for calculating the physical record address of the auxiliary storage device, a register for storing the physical record address of the auxiliary storage device, and a register for storing the auxiliary storage device address.

[Operation] By providing the above-mentioned means, in the present invention,
Store the device address and record address in the logical device address register and logical record address register, then use the divider to divide the value of the logical record address register by the value of the physical device number register, and use the remainder as the physical device address. Find by. Also,
・The code address is obtained by calculating the first physical record address from the device address value of the logical device address register using the address conversion table, and adding it to the previously calculated quotient of the divider (relative physical record address) in the adder. calculate.

[Embodiment] FIG. 1 shows the configuration of an apparatus for implementing the method of the present invention, in which 1 represents a processor and memory, 2 represents a channel, 3 represents an auxiliary storage controller, and 4 represents an auxiliary storage device.

Figure 2 shows the above 1rI! FIG. 2 is a diagram illustrating the correspondence between records and addresses when allocating files according to the method of the present invention in the auxiliary storage device 4, which is an element constituting the device J.

In FIG. 2, for a plurality of auxiliary storage devices 4,
n physical device addresses of PO% Pl and *s*Pn-1 are given.

On the other hand, a plurality of logical devices 401 are set across each auxiliary storage device 4, and the logical device address L1
% L2, . . . L m −1, are given.

The auxiliary storage device 4 has a large number of tracks, and each track is further divided into one record 402 and managed. Therefore, each physical device and logical device is
It will consist of many records. In order to manage these records both physically and logically,
As shown in the general format at the bottom left of FIG. 2, each record 402 is assigned a unique logical record address and physical device address.

Throughout Figure 2, the symbol written at the top of the rectangle indicating a record is a logical record address, as is clear from the general format, and similarly, the symbol written at the bottom of the rectangle is
The symbol of the physical device address is written.

As can be seen from FIG. 2, the internal physical record address of each auxiliary storage device 4 is 0. 1. 2. Fist..., r-1° then rl
rl1. rl2. ..., 2r-1), but logical record addresses are not simply assigned to records by dividing a file, but logical record numbers 402 are given in the order of physical Assign record interleaving to device 4.

Here, for reference, conventionally known interleaps will be outlined. FIG. 4a shows a plurality of memory modules MMl to MM4 that can operate independently.
It is assumed that it is connected to the central processing bag flcPU via an interface unit.

In such a device, when programs and data are sequentially stored in each memory module as shown in Figure 4, access may be concentrated on a specific memory module, depending on the nature of the stored program. There is a strong tendency that only a portion of the memory cycles will be used for access, reducing efficiency.

To avoid this, if the memory is distributed and allocated to each memory module as shown in FIG. 4C, access will also be distributed and access efficiency will be improved. This allocation method is called interleaving.

The allocation procedure in the embodiment of the present invention will be explained with reference to FIG. As is clear from the above explanation, the number of physical devices used is n, and the logical record RO1R
11...Rn-1 as physical device PO1pt
, ...*Sequentially allocate to the same physical record address of Pn-1 (O in the example of FIG. 2).

Next logical record Rn1Rn+1s a @ @
R2n-1, respectively, to the physical device PO1P! ,・
. . , are sequentially allocated to the address obtained by adding 1 to the physical record address (0 in the example) of P n-1 (O+1=1 in the example). Thereafter, this procedure is repeated in the same way to allocate logical records to physical record addresses.

FIG. 3 is a diagram illustrating the conversion of a logical device address to a physical device address according to the scheme of the present invention. In the figure, 301 is a register that stores a logical device address sent from a channel, 302 is a register that stores a logical record address that is sent as data from a channel, and 303 is a physical device stored in an auxiliary storage control unit. 304 is a conversion table between the logical device address and the first physical record address; 305 is a divider for calculating the physical device address from the logical record address; 306 is for calculating the physical record address in the physical device. 307 is a register that stores the physical record address of the auxiliary storage device, and 308 is a register that stores the auxiliary storage device address.

Next, the operation of the circuit shown in FIG. 3 for converting logical device addresses and logical record addresses into physical device addresses and physical record addresses will be explained.

The device address and record address sent from channel 2 are stored in the logical device address register 301 & logical record address register 302. next,
Logical record address register 30 by divider 305
The value of 2 is divided by the value of the physical device number register 303, the remainder is sent to the physical device address register 308, and the quotient is sent to the adder 306. Note that in the physical device number register 303, the number of mounted devices can be set by hardware means such as a dip switch, but it can also be set by a software command.

The physical record address is obtained by calculating the first physical record address from the value of the logical device address register 801 using the address conversion table 304, and using the previously calculated divider 3.
05 quotient (relative physical record address) and adder 306
It is calculated by adding in the physical record address register 307 and stored in the physical record address register 307.

Note that the address conversion table 304 may be read from a specific physical device 4 and stored when the power is turned on, or
The data may be stored in accordance with a command instruction from software.

[Effects of the Invention] As is clear from the above explanation, the interleaving method of the present invention allows the system designer to automatically equalize the load on each physical device without having to consider load equalization. In addition, by using an allocation means that makes a few large-capacity physical devices appear to be many physical devices, it is possible to eliminate the bottleneck of the exclusive control section of large-capacity devices on a device-by-device basis.

This prevents unbalanced loads between physical devices and allows logical devices to be extracted with a number of records that will not cause a device bottleneck. Moreover, the excellent effect of being able to utilize the entire capacity of the physical device for growth efficiency and improving the total throughput can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the system configuration of an embodiment of the present invention, FIG. 2 is a diagram showing an example of allocation of logical devices to physical devices of the present invention, and FIG. 3 is a diagram showing logical device addresses of the present invention. FIG. 4 is a diagram illustrating the principle of interleaving. 1: Processor and memory 2: Channel 3: Auxiliary storage control device 304 Near address conversion table 4: Auxiliary storage device 401: Logical device 402 Near record

Claims (1)

[Claims] In an auxiliary storage control device that controls allocation by interleaving successive records in a logical device by the number of physical devices, a correspondence relationship between a logical record address and a first physical record address for each logical device is stored. It consists of a physical record address conversion table, a circuit that converts a logical record address and the number of physical record addresses to a physical device address, and a circuit that converts the first physical record address and relative physical record address to a physical record address. Based on the logical device address and logical record address, the physical device address is the remainder obtained by dividing the logical record address by the number of physical devices, and the sum of the relative physical record address and the logical device address, which is the quotient, is used as the physical record address. A peripheral device access method characterized by accessing a device.