JPH06187249A - Disk array device - Google Patents

Abstract

PURPOSE:To utilize mutual advantages to improve the throughput and to shorten the read/write time of a disk drive by switching RAID levels according to the amount of data. CONSTITUTION:When data are written or read, a host sends a command to a disk array through a host interface 5, a data bus 6, and a control bus 7. The command contains data on an operation indication, the length of data, the level of RAID, an address, etc., on a medium on the disk drive, etc. On receiving the command, the disk array judges which level of the RAID operation is performed by a microcomputer 91 and sends an indication to a RAID level setting circuit 11 through a RAID switching indication signal line 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk array device.

[0002]

2. Description of the Related Art "A Case for Redund"
ant Arrays of Inexpensive
Disks (RAID) ”(Technical R
eport UCB / CSD 87/391, Dece
mber 1987) RAID 1-5 have been proposed.

FIG. 3 is a block diagram of a conventional disk array device belonging to RAID3 and RAID5. The disk array device, five magnetic disk drive (hereinafter referred to as "disk drive".) And 1 ₁ to 1 _5, a device data bus 2 ₁ to 2 ₅ connected to the respective disk drives 1 ₁ to 1 _5, the device data bus 2 ₁ to 2 ₅ and the device interface 3 ₁ to 3 ₅ connected to the respective disk drives 1 ₁ to 1 ₅ through the array data bus 4 ₁ connected to each device interface 3 ₁ to 3 ₅ ~
And 4 _5, a host interface 5 connected to the host
A host data bus 6 connected to the host interface 5, a control bus 7 connected to the host interface 5, and device interfaces 3 _{1 to} 3 ₅ via the array data buses 4 ₁ to 4 _5. Connected to the host interface 5 via the host data bus 6 and connected to the device interfaces 3 _{1 to} 3 ₅
Array controller 8 for controlling writing / reading of data to / from the disk drives 1 ₁ to ₁₅ via the
_2, the microcomputer 9 ₃ for controlling the array controller _82, RAID switch connected to the array control bus 10 which is connected to the array controller ₈₂ and the microcomputer 9 _3, and the microcomputer 9 ₃ A RAID level setting circuit 11 for setting a RAID level in advance by an instruction signal line 13 and a RAID level connection circuit 11 connected to the RAID level setting circuit 11 and connected to the array controller 8 _2.
It is composed of the D level signal line 12.

[0004]

In the above-mentioned conventional disk array device, the RAID level is fixed and used. Therefore, if the RAID level is fixed to 3, the write efficiency of random file writing / reading will decrease. There is a problem that the speed becomes slow, and if the RAID5 is fixed, the processing efficiency decreases due to the writing / reading of the sequential file, and the processing speed decreases.

The object of the present invention is to determine the RAI according to the amount of data.
By switching the D level, the advantage of RAID having two different levels is utilized to improve the processing efficiency, and to provide a disk array device with a short write / read time for the disk drive.

[0006]

In order to achieve the above object, the present invention provides a host interface connected to a host computer, an array controller controlled through this host interface, and an N controlled by this array controller. RAID level setting for setting a RAID level in a disk array device having a number (N is an integer of 2 or more) of device interfaces and N disk drives controlled through each of the N device interfaces. A circuit, a RAID level switching instruction signal line connecting the microcomputer and the RAID level setting circuit, and the RAID
A RAID level signal line for connecting the level setting circuit and the array controller is provided, and in accordance with a RAID level instruction included in an operation command from the host computer, the microcomputer sends the signal through the RAID level switching instruction signal line. , Setting the RAID level of the RAID level setting circuit to switch between two levels of RAID data on the same disk drive for writing / reading, and further from the microcomputer via an address bus and a data bus. A non-volatile memory to be connected is added, and R is set according to the amount of data included in the operation command from the host computer
A function of changing the AID level to write data to the disk drive, a function of recording the address of the data on the disk drive, the data capacity, and the RAID level, and an operation command from the host computer. A disk array device is additionally provided with a function of reading the data of the disk drive by setting the RAID level recorded in the nonvolatile memory by the microcomputer from the address included in the operation command when reading the data.

[0007]

Therefore, since a data file having a large amount of data can be written in, for example, RAID3 and a file having a small amount of data can be written in, for example, RAID5, the processing efficiency is improved and the time required for writing / reading to / from the disk drive is increased. It gets shorter.

[0008]

[Example] 1. 1 is a block diagram of a disk array device according to a first embodiment of the present invention. Blocks with the same numbers as in FIG. 3 have the same functions.

When writing / reading data,
The host sends an operation command in the form of a command to the disk array via the host interface 5, the data bus 6 and the control bus 7. The command includes data such as an operation instruction, a data length, a RAID level, and an address on the medium of the disk drive.
Upon receiving the command, the disk array receives RAID3
Or RAID5 to determine operating in Kano either level microcomputer 9 ₁ sends an instruction to the RAID level setting circuit 11.

In this embodiment, it is assumed that a command for writing a data file of 32 kilobytes in RAID3 to the disk drive is sent from the host.

When a write command is sent from the host, the microcomputer 9 ₁ sends an instruction to the RAID level setting circuit 11 via the RAID switching instruction signal line 13 to set RAID 3. The RAID level setting circuit 11 indicates that the RAID level setting circuit 11 operates in RAID3.
Output to the D level signal line 12. The microcomputer 9 ₁ sends a data transfer start instruction to the array controller 8 ₁ via the array control bus 10. Array controller ₈₁ refers to the RAID level signal line 12, the data from each array data bus ₄₁ to ₅ in the data structure of RAID3 sent from the host, the device interface 3 ₁ to 3 ₅ and device data Bus 2
Transferred to the respective disk drives ₁ 1 to 1 ₅ through 21 _{to 5.} Array controller _81, when the data transfer is completed, the completion report from the array control bus 10 to the microcomputer 9 _1, end report to the host microcomputer 9 ₁ through the host interface 5 and the data bus 6 and control bus 7 I do.

2. FIG. 2 is a block diagram of a disk array device according to the second embodiment of the present invention. Blocks with the same numbers as in FIG. 3 have the same functions.

In this embodiment, the nonvolatile memory 14 for recording the address of the data to be written on the disk drive, the RAID level and the data capacity.
An address bus 15 for accessing the nonvolatile memory 14 is added to the embodiment of FIG.

When writing / reading data, the host sends an operation command in the form of a command to the disk array via the host interface 5, the data bus 6 and the control bus 7. Operation command during command,
It includes data such as the data capacity and the address on the medium of the disk drive. Upon receiving the command, the disk array determines the RA from the data capacity of the data file.
The microcomputer 9 ₂ determines whether it is ID3 or RAID5. R if the data capacity is less than 8 kilobytes
If the number of AIDs is larger than 8 kilobytes, the microcomputer 9 ₂ sends an instruction of RAID ₃ to the RAID level setting circuit 11, and the address written in the medium of the disk drive via the data bus 6 and the address bus 15 and the RAID level and The data capacity and the non-volatile memory 14 are recorded.

In the present embodiment, a command is sent from the host to write a 4-kilobyte data file to the disk drive address "0", and a command to read 4-kilobyte data from the disk drive address "0" after the writing process is completed. Shall be sent.

[0016] write from the host command is sent, the microcomputer 9 ₂ transmits an instruction via the RAID switching instruction signal line 13 to set the RAID5 RAID level setting circuit 11, the data bus 6 and the address bus The address “0” to be written on the disk drive medium, the RAID5 mode and the data capacity are recorded in the non-volatile memory 14 via 15.
The RAID level setting circuit 11 outputs to the RAID level signal line 12 that it operates in RAID5. The microcomputer 9 ₂ sends a data transfer start instruction to the array controller 8 ₁ via the array control bus 10. The array controller 8 ₁ refers to the RAID level signal line 12 and outputs the data sent from the host to the RAI.
From each array data bus ₄₁ to ₅ in the data structure of D5, the disk drive 1 via the respective device interface 3 ₁ to 3 ₅ and the device data bus 2 ₁ to 2 ₅
Transfer to ₁ to ₁₅ . Array controller _81, when the data transfer is complete, it ends the array control bus 10 to the end report to the microcomputer 9 _2, to the host via the microcomputer 9 ₂ and host interface 5 and the data bus 6 and control bus 7 A report is made and the write process ends. Next, when a command to read the data of four kilobytes address "0" of the disk drive from the host is sent, the microcomputer 9 _2, the data bus 6 and the address bus 15 the address from the non-volatile memory 14 of the disk drive via the " Read the capacity of the data written to 0 "and the RAID level and set it to RAID5.
An instruction is sent to the RAID mode setting circuit 11 via the D switching instruction signal line 13, and the RAID level setting circuit 11
Outputs to the RAID level signal line 12 that it operates in RAID5. The microcomputer 9 ₂ receives the array controller 8 ₁ via the array control bus 10.
Send an instruction to start data transfer to. Array controller 8
₁ refers to the RAID level signal line 12 and refers from each disk drive 1 ₁ to ₁₅ to each device data bus 2 ₁ to 2
₅ and each device interface 3 _{1 to} 3 ₅ and each array data bus 4 ₁ to 4 ₅ to read data,
The data of ID5 is converted into the configuration when written from the host, and transferred to the host via the data bus 6 and the host interface 5. Array controller 8 ₁
When the data transfer is completed, the completion report from the array control bus 10 to the microcomputer 9 _2, the termination report to the host via the microcomputer 9 ₂ and host interface 5 and the data bus 6 and control bus 7.

[0017]

As described above, by using the disk array device of the present invention, two levels of RAID can be obtained.
Since the advantages of each other can be utilized and the drawbacks can be compensated for, a disk array device having high processing efficiency and a short processing time can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram of a disk array device according to a first embodiment of this invention.

FIG. 2 is a block diagram of a disk array device according to a second embodiment of the present invention.

FIG. 3 is a block diagram of a conventional example of a disk array device.

[Explanation of symbols]

1 ₁ to 1 ₅ disc drive 2 ₁ to 2 ₅ device data bus 3 ₁ to 3 ₅ the device interface 41 _{to 5} array data bus 5 host interface 6 the data bus 7 control bus 8 _1, 8 ₂ array controllers 91 _to 93 ₃ Microcomputer 10 Array control bus 11 RAID level setting circuit 12 RAID level signal line 13 RAID switching instruction signal line 14 Non-volatile memory 15 Address bus

Claims (2)

[Claims] 1. A host interface connected to a host computer, an array controller controlled through the host interface, N (N is an integer of 2 or more) device interfaces controlled by the array controller, and the N In a disk array device having N disk drives controlled through each of the device interfaces, a RAID level setting circuit for setting a RAID level and a RAID connecting the microcomputer and the RAID level setting circuit Level switching instruction signal line and the RAID
A RAID level signal line for connecting the level setting circuit and the array controller is provided, and in accordance with a RAID level instruction included in an operation command from the host computer, the microcomputer sends the signal through the RAID level switching instruction signal line. A disk array device characterized by setting the RAID level of the RAID level setting circuit and switching between two levels of RAID data on the same disk drive for writing / reading. 2. The disk array device according to claim 1, wherein a nonvolatile memory connected from the microcomputer via an address bus and a data bus is added, and data contained in an operation command from the host computer is added. A function of changing the RAID level according to the capacity to write data to the disk drive, a function of recording the address of the data on the disk drive, the capacity of the data and the RAID level, and the operation from the host computer. When the data is read by the instruction, the RAI recorded in the nonvolatile memory by the microcomputer from the address included in the operation instruction.
A disk array device with a function to read data from a disk drive by setting it to D level.