CN1601484A

CN1601484A - Disk data backup system and method thereof

Info

Publication number: CN1601484A
Application number: CN 03159567
Authority: CN
Inventors: 牛仁朝; 张明; 郭晓川
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2003-09-23
Filing date: 2003-09-23
Publication date: 2005-03-30
Anticipated expiration: 2023-09-23
Also published as: CN100383757C

Abstract

The invention realizes data backup function based on multiple mirrored hard discs by using only one ATA interface so that operation of data backup is independent from operation system on host. The magnetic disc backup system includes general hard disc controller, several hard discs in identical specification, and data backup circuit module. The said general hard disc controller provides a high technical attachment unit interface, and connection between attachment unit interface and the data backup circuit module. The data backup circuit module extends a high technical attachment unit interface into several identical high technical attachment unit interfaces. The said attachment unit interface determines correctness of data read from several said hard discs. Each extended high technical attachment unit interface is connected to a hard disc.

Description

Disk data backup system and method thereof

Technical Field

The present invention relates to a data backup technology, and more particularly, to a technology for backing up data using a disk.

Background

In recent decades, with the development of computer technology, the processing speed of a Central Processing Unit (CPU) has been increased by many times, and the speed of the CPU has entered the GHz era; the Access speed of a Memory (Memory) is also greatly increased, the operating frequency of the Memory is increased from 66MHz to 100MHz or even 133MHz, a leap from a Dynamic Random Access Memory (DRAM) to a Double-Rate DRAM (DDR DRAM) appears in the manufacturing technology, and the Access speed of the DRAM can be doubled without increasing the operating frequency.

The data storage device, mainly a hard disk (hard disk), only increases the access speed by several times, forms the bottleneck of the computer system, lowers the overall performance of the computer system, and if the access speed of the hard disk cannot be effectively increased, the improvement of the CPU and the memory is greatly wasted due to the imbalance among the CPU, the memory and the hard disk. Since the speed of the hard disk is greatly dependent on the mechanical part, it is very difficult to greatly increase the speed based on the current hard disk technology.

On the other hand, information security is more and more important, once data of a hard disk is damaged, important data can be destroyed once, so that double backup or multiple backups are needed for data in the fields of finance, securities, telecommunication bill backup and the like, namely, the data is required to have redundancy, and uninterrupted, reliable and real-time data backup is required to be provided.

At present, most of hard disks used by Personal computers (Personal computers, abbreviated as "PCs") are compatible with Integrated Drive Electronics (IDE), and only one cable is needed to connect the hard disks with a mainboard or an interface card. IDE actually refers to a hard disk drive that integrates a controller with a disk body, thus reducing the number and length of cables for a hard disk interface, enhancing reliability of data transmission, making a hard disk easier to manufacture, and making it more convenient for a user to install. The IDE interface is also called an Advanced Technology Attachment (ATA) interface.

In order to increase the capacity of a data storage system and the speed of transmitting data, and ensure the redundancy of data to backup data, the existing solution generally adopts a Redundant Array of Independent Disks (RAID) technology.

Different technologies are adopted correspondingly according to different applications of the disk array. RAID technologies are largely divided into RAID0, RAID1, RAID3, RAID4, and RAID 5. Among them, RAID0 is used to increase access speed, and RAID1 is used for backup of data.

RAID0 implementation requires more than two hard disk drives, and RAID0 does not store data on one hard disk, but rather, stores data in blocks on different drives. Because the data is distributed on different drivers, the data throughput rate is greatly improved, and the loads of the drivers are balanced. If just the required data is best efficient on a different drive. It does not need to calculate check code, and is easy to implement. It has the disadvantage that it has no data error control and if data in one drive is erroneous, it does nothing to do if the data on the other disc is correct. Meanwhile, RAID0 may increase the data transfer rate, for example, files that need to be read are distributed on two hard disks, and the two hard disks may be read simultaneously. The time to read the same file is shortened to 1/2.

RAID1 employs a Peripheral Component Interconnect (PCI) BUS, a Small Computer System Interface (SCSI) BUS, or a Local BUS (Local BUS) to generate read and write control for the disk arrays, as shown in fig. 1. The two hard disks have the same specification and are mirror-matched with each other, when the main hard disk is damaged, the mirror hard disk can replace the main hard disk to work, and the mirror hard disk is equivalent to a backup disk. When the central processing unit reads and writes the hard disks, the speed of writing data is the same as that of reading and writing one hard disk, but when reading the data, the two hard disks are read out simultaneously, and the speed is doubled. RAID1 can guarantee the reliability and repairability of the system to the utmost extent under the condition of not influencing the performance, and the safety and fault-tolerant capability of the system are improved. Under RAID1, the failure of any hard disk will not affect the normal operation of the system, and even half of the hard disks can work uninterruptedly when there is a problem. When one hard disk fails, the system ignores the hard disk and continues to keep the normal operation of the system.

The redundant array of independent disks technology using the SCSI bus is generally used for larger systems, has higher cost and is less adopted at ordinary times. Most of daily use is IDE hard disks, so IDE RAID is most closely attached to us and is limited to low application level, and most of IDE RAID only supports a few RAID technologies such as RAID0, RAID1 and the like.

In practical applications, the above scheme has the following problems: RAID technology presents software and hardware compatibility issues and potentially increases the system's instability factor, and RAID technology cannot be employed to implement data backup in some specific systems.

One of the main reasons for this is that, firstly, the RAID technology uses PCI bus, SCSI bus, or local bus to generate read/write control of the disk array, and its driver has a relationship with the host and the operating system used by the host, so there are problems of compatibility between software and hardware and potentially increasing the unstable factor of the system; secondly, in some data storage systems, the local bus is not opened, the system does not provide a PCI expansion port or a SCSI expansion port, and only one hard disk is hung on one ATA interface, and at this time, the system cannot adopt RAID technology to realize disk data backup.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a disk data backup system and a method thereof, so that data backup is independent of an operating system of a host, and the data backup function based on a plurality of mirror image hard disks is realized by only using one ATA interface.

In order to solve the above technical problem, the present invention provides a disk data backup system, which comprises a common hard disk controller and a plurality of hard disks with completely the same block size, and further comprises: a data backup circuit module;

the common hard disk controller is used for providing an advanced technology attachment interface and is connected with the data backup circuit module through the advanced technology attachment interface;

the data backup circuit module is used for expanding an advanced technology accessory interface into at least two completely same advanced technology accessory interfaces, each expanded advanced technology accessory interface is connected with one hard disk, when data is written in, the same data is written in each hard disk, when data is read out, the correctness of each path of read data is judged, and one path of read data is selected to be output.

The system also comprises a central processing unit which is connected with the ordinary hard disk controller through a system bus and is used for controlling the ordinary hard disk controller.

And the data backup circuit module sends out an alarm signal when an error occurs.

And converting other types of interfaces into advanced technology accessory interfaces, and then performing data backup by using the data backup circuit module.

The data backup circuit module comprises: a first duplicator, a second duplicator, a first selector, a second selector, a comparator and a control signal generator;

the first duplicator and the second duplicator respectively duplicate the signals of the address/chip selection bus and the data bus of the advanced technology attachment interface output by the common hard disk controller into at least two paths of completely same signals of the address/chip selection bus and the data bus of the advanced technology attachment interface, and respectively output the output signals of the address/chip selection bus and the data bus of each path of advanced technology attachment interface to the input ends of the address/chip selection bus and the data bus of the advanced technology attachment interface of one hard disk through buses;

the first selector and the second selector are used for respectively selecting one path from data signals on data buses and control signals on control buses of advanced technology attachment interfaces of at least two paths of hard disks according to respective control end signals of the first selector and the second selector, and the first selector and the second selector are respectively connected to a data bus input/output end and a control bus input end of an advanced technology attachment interface of the common hard disk controller through buses; the control end signals of the first selector and the second selector are both generated by the control signal generator and output to the control ends of the first selector and the second selector;

the comparator is used for comparing a plurality of paths of input data signals on the data bus of the advanced technology attachment interface of the hard disk and outputting a comparison result to the input end of the control signal generator;

the control signal generator is used for judging the correctness of the plurality of paths of data/states according to the relevant protocol and generating a control signal.

The second selector outputs a control signal indicating that the hard disk is not ready as long as there is a control signal of the hard disk indicating that the hard disk is not ready.

The data backup circuit module further comprises: the alarm generator is connected with the control signal generator; the alarm generator is used for generating an alarm signal when one hard disk has an error.

When the alarm generator generates an alarm signal, the working state of the hard disk is indicated by an indicator light and the central processing unit is informed by other interfaces.

The invention also provides a method for reading and writing data of the disk data backup system, which comprises the following steps:

when the advanced technology attachment interface writes data/parameters into the hard disk, the data/parameters are copied into two identical paths and are respectively written into the two hard disks;

b, when the advanced technology attachment interface reads data/states from the hard disks, firstly judging whether the data/states of the two hard disks are consistent, if so, reading the data/state of any hard disk, otherwise, entering the step C;

and C, judging whether both the two paths have errors, if so, selecting one path to the advanced technology attachment interface data bus and initiating re-reading and writing or carrying out hard disk diagnosis processing by the central processing unit, and otherwise, selecting one path of correct data/state to be sent to the advanced technology attachment interface data bus.

The difference between the technical scheme of the invention and the prior art can be found by comparing the technical scheme of the invention, namely, a data backup module is added to directly convert a path of ATA interface into a plurality of paths of ATA interfaces, each sub-interface of each ATA interface is connected with a hard disk with the same specification, and the hard disks are mirror images.

The difference of the technical scheme brings obvious beneficial effects, namely, the disk data backup scheme provided by the invention is independent of the host and the operating system used by the host, can be directly used without changing the host and the operating system of the host, realizes seamless connection with the existing system, enables the operation of disk data backup to be simpler and more convenient, and can realize disk data backup without changing or upgrading the system for the existing system which cannot realize data backup because a bus expansion port is not provided, thereby saving the complex operation of changing or upgrading the system and saving the cost.

Drawings

FIG. 1 is a system architecture diagram of a conventional RAID technology 1;

FIG. 2 is a block diagram of a disk data backup system in accordance with an embodiment of the present invention;

FIG. 3 is a schematic diagram of a data backup circuit module in a disk data backup system according to an embodiment of the present invention;

FIG. 4 is a timing diagram of hard disk read/write operations of a disk data backup system according to an embodiment of the present invention

Fig. 5 is a flowchart illustrating a data reading and writing process of a disk data backup system according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings.

The invention realizes the expansion of one ATA interface to a plurality of ATA interfaces by adding a data backup circuit, thereby realizing the backup of data by utilizing the expanded ATA interface.

The invention will now be described with reference to a specific embodiment thereof. This embodiment extends one ATA interface to two ATA interfaces and enables the backup of data.

The structure of a disk data backup system according to an embodiment of the present invention is shown in fig. 2.

The disk data backup system comprises: a central processor 10, a general hard disk controller 20, a data backup circuit module 30 and a hard disk 40.

The central processing unit 10 is connected to the general hard disk controller 20 through the PCI bus, the general hard disk controller 20 is configured to provide an ATA interface to connect to the data backup circuit module 30, the data backup circuit module 30 expands the ATA interface into two ATA interfaces, each expanded ATA interface is connected to one hard disk 40, and the same data is accessed to realize data backup, and there are two hard disks 40 that are mirror images of each other.

The data backup circuit module 30 is a newly added module of the present invention, and is used to expand the address/chip select bus, the data bus and the control bus of the ATA interface into two identical parts of the address/chip select bus, the data bus and the control bus of the ATA interface, respectively, judge the correctness of the read data and select the data output when reading data from two hard disks, and send out a corresponding alarm signal when an error occurs. The data backup Circuit module 30 can be implemented in many ways, such as by a Field Programmable Gate Array (FPGA), a Printed Circuit Board (PCB), or a Digital Signal Processor (DSP), and part of the Circuit is implemented by the FPGA. It will be understood by those skilled in the art that, according to the same principle, the data backup circuit may extend one ATA interface to a plurality of ATA interfaces, each extended ATA interface being connected to one hard disk 40, and also may implement data backup, where all hard disks access the same data. Note that the specifications of the two hard disks 40 in fig. 2 are completely the same.

It will be understood by those skilled in the art that if the data backup is performed by other types of interfaces, the data backup circuit of the present invention can be used to perform the data backup by converting the data backup into the ATA interface.

The internal circuit schematic of the data backup circuit module 30 is shown in fig. 3.

The data backup circuit module 30 includes: a duplicator 31, a duplicator 32, a selector 33, a selector 34, a comparator 35, a control signal generator 36 and an alarm generator 37.

The duplicator 31 is used for duplicating the ATA address/chip select bus signals output by the ordinary hard disk controller 20 into two paths of completely identical ATA address/chip select bus signals when reading and writing the hard disk 40, and respectively connecting each path of the output ATA address/chip select bus signals with an ATA address/chip select bus input end of the hard disk 40 through the bus. For example, in a preferred embodiment of the present invention, when reading data from a certain address of the hard disk, the normal hard disk controller 20 outputs an address/chip select signal on the ATA address/chip select bus, and the duplicator 31 duplicates the address/chip select signal into two identical address/chip select signals and inputs the duplicated address/chip select signals into two identical hard disks 40 through the bus.

The duplicator 32 is used for duplicating the ATA data bus signals received from the ATA data bus input/output terminal of the ordinary hard disk controller 20 into two paths of identical ATA data bus signals when writing data into the hard disk 40, and connecting each path of output ATA data bus signals to the ATA data bus input/output terminal of one hard disk 40 through the bus. For example, in a preferred embodiment of the present invention, when data needs to be written into the hard disk 40, a data signal to be written is generated on the ATA data bus of the normal hard disk controller 20, and the duplicator 32 duplicates the signal into two identical ATA data bus signals and inputs the signals to the data bus input/output terminals of the two hard disks 40, respectively.

The selector 33 is used for selectively inputting the data signals on the data buses of the two hard disks 40 to output to the ATA data bus input/output terminal of the ordinary hard disk controller 20 through the buses according to the control terminal signal of the selector 33 when reading data from the hard disk 40. Wherein the control terminal signal of the selector 33 is generated by the control signal generator 36. For example, in a preferred embodiment of the present invention, when data needs to be read from the hard disks 40, the two hard disks 40 respectively read data and output the data to the input terminal of the selector 33, and the selector 33 selects one of the data outputs according to the control terminal signal.

The selector 34 is used for selecting the control signals on the ATA control buses of the two hard disks 40 to be input and output to the ATA control bus input end of the ordinary hard disk controller 20 through the bus according to the control end signal of the selector 34 when the hard disk 40 reads and writes data. For example, in a preferred embodiment of the present invention, when reading and writing data, the selector 34 selects the ATA control signals of the two hard disks 40 to be output according to the control end signal, and the output signal may be a control signal such as an input/output ready signal (IORDY).

The comparator 35 is used for comparing the input data signals on the data buses of the two hard disks 40 when reading data from the hard disk 40 and outputting the comparison result to one input end of the control signal generator 36. For example, in a preferred embodiment of the present invention, the comparator 35 compares the two input data signals, and if they are consistent, the output is 0, and the inconsistent output is 1.

The control signal generator 36 is used for judging which of the two paths of data/states is correct according to the relevant protocol, and accordingly generating two paths of control signals to respectively control the selector 33 to select data and the selector 34 to select state output. Specific protocols can refer to T131321D Information Technology-ATAttachment with Packet Interface-5(ATA/ATAPI-5), and Chinese can be translated into T131321D Information Technology-advanced Technology attachment Interface with Packet Interface-5, referred to as ATA/ATAPI-5.

The alarm generator 37 is used for generating an alarm signal when an error occurs in one of the hard disks 40. The alarm signal can indicate the working state of the hard disk by using an indicator light and can also be told to the CPU by other interfaces. For example, in a preferred embodiment of the present invention, when an error occurs in one of the hard disks 40, the alarm lamp is turned on and an alarm buzzer is sounded.

It will be appreciated by those skilled in the art that one ATA interface can be extended to more than two ATA interfaces and the backup of data can be implemented in accordance with the same principles. In this case, the number of copy output paths of the

duplicators

31 and 32 is increased; the two-way input selector of the selector 33 and the selector 34 is improved into a multi-way input selector; the comparator 35 is changed from a two-way input comparator to a multi-way input comparator; the comparison and judgment protocol in the control signal generator 36 is not changed, and the output control signal is slightly changed.

It can be seen from the above principle that, in the present invention, one ATA interface is duplicated into several identical ATA interfaces to implement data backup, which is independent of the signals of the ATA interfaces, so that the present invention is not only suitable for the data read/write in ATA programmable input/Output (PIO) mode of hard disk, but also suitable for the data read/write in Direct Memory Access (DMA) mode.

The read/write timing of a hard disk in a programmable input/output (PIO) mode is shown in fig. 4. In fig. 4, the open bars represent the active state and the corresponding single horizontal line represents the inactive state, i.e., the high impedance state.

The Chip select/address signals include CS (1:0) and DA (2:0), CS in CS (1:0) refers to Chip select for selecting a command block or a control block register of the hard disk 40, DA in DA (2:0) refers to Deviceaddress for designating a register or a data port of the hard disk 40. In a preferred embodiment of the present invention, two hard disks 40 that are mirror images of each other receive the same chip select/address signal.

A data input/output read signal, i.e., DIOR-, refers to a Device I/O read, which is a strobe signal for reading a register of the hard disk 40 or a data input/output port, and the low level is valid; the data input/output write signal, i.e., DIOW-, refers to Device I/O write, is a strobe signal that writes to a register or data input/output port of the hard disk 40, and is active low.

The write Data or read Data signal, DD (15:0), DD in DD (15:0) refers to Device Data, is Data that is passed between hard disk 40 and the host, and may be 8 bits or 16 bits wide. In a preferred embodiment of the present invention, when reading data from the hard disk, the read data signals DD (15:0) may be different, and it is necessary to determine to select one of the outputs.

The I/O ready signal IORDY, referred to as I/O channel ready, when low indicates that the hard disk 40 is not ready to input or output data, requiring the host to add wait states. This signal is generated by the selector 34 and is low as long as a hard disk 40 is not ready. For example, in a preferred embodiment of the present invention, as long as the IORDY signal of one hard disk is low, the host is notified to increase the wait state, that is, the signal indicating that IORDY is low is output to the normal hard disk controller 20.

The signals and timing AT the time of input/output can be referred to T131321D information technology-AT Attachment with Packet Interface-5 (ATA/ATAPI-5).

The working flow of the disk data backup system when reading and writing data according to an embodiment of the present invention is shown in fig. 5.

Step 110 is entered first to determine if the ATA is writing data/parameters, if yes, step 120 is entered, otherwise step 130 is entered. In a specific implementation, the state of DIOW-is determined to determine whether ATA is writing data/parameters.

In step 120, the data/parameters are divided into two identical paths and written to the two hard disks respectively. In this step, the backup of the data is completed, and the storage data which are mirror images of each other are formed.

In step 130, it is determined whether the ATA is reading data/state, if so, step 140 is entered, otherwise the process ends. In a specific implementation, the state of DIOR-is determined to determine whether the ATA is in read data/state.

In step 140, it is determined whether the data/status of the two hard disks are consistent, if yes, step 150 is entered, otherwise step 160 is entered. This step is required in order to increase the reliability of data reading to prevent data from being changed during storage, which results in reading erroneous data.

In step 150, the data/status of an optional hard disk is read. At this time, the data/state output by the two hard disks is consistent, which indicates that the data/state of any hard disk is correct, so that any one output is optional.

In step 160, it is determined whether the data/status of the two hard disks is completely wrong, if yes, step 180 is entered, otherwise, step 170 is entered. The step is determined according to the relevant protocol, which can be specifically referred to as "T131321D Information Technology-AT Attachment with packet interface-5 (ATA/ATAPI-5)").

In step 170, the correct data/status is sent to the ATA data bus.

In step 180, an optional data/status is passed to the ATA data bus. At this time, because two paths of data/states are wrong, selection is not needed to be made, and one path of data is selected to be output. Step 190 is then entered.

In step 190, the CPU initiates a read/write resume or a hard disk diagnostic process.

Thus, the process of reading/writing the hard disk once is completed.

Through the above read-write process, those skilled in the art can understand that the probability of simultaneous error of two hard disks is very small, so that the invention greatly improves the safety degree of data storage.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A disk data backup system comprises a common hard disk controller and a plurality of hard disks with the same specification, and is characterized in that the system also comprises a data backup circuit module, wherein,

the data backup circuit module is used for expanding an advanced technology attachment interface into at least two completely same advanced technology attachment interfaces, each expanded advanced technology attachment interface is connected with one hard disk, and

when writing data, writing the same data into each hard disk; when the data is read, the correctness of the read data of each path is judged, and one path is selected for output.

2. The disk data backup system according to claim 1, further comprising a central processor connected to said normal hard disk controller via a system bus for controlling said normal hard disk controller.

3. The disk data backup system of claim 1 wherein the data backup circuit module issues an alarm signal when an error occurs.

4. The disk data backup system according to claim 2, wherein said data backup circuit module comprises: a first duplicator, a second duplicator, a first selector, a second selector, a comparator and a control signal generator; wherein,

the first duplicator and the second duplicator are used for respectively duplicating the signals of the address/chip selection bus and the data bus of the advanced technology attachment interface output by the common hard disk controller into at least two paths of completely same signals of the address/chip selection bus and the data bus of the advanced technology attachment interface, and respectively outputting the output signals of the address/chip selection bus and the data bus of each path of advanced technology attachment interface to the input ends of the address/chip selection bus and the data bus of the advanced technology attachment interface of one hard disk through buses;

5. The disk data backup system according to claim 4 wherein said second selector outputs a control signal indicating that said hard disk is not ready when a control signal from at least one of said hard disks indicates that said hard disk is not ready.

6. The disk data backup system according to claim 4, wherein said data backup circuit module further comprises an alarm generator connected to said control signal generator, wherein said alarm generator is configured to generate an alarm signal when an error occurs in one of said hard disks.

7. The disk data backup system of claim 6, wherein when the alarm generator generates an alarm signal, an indicator light is used to indicate the operation status of the hard disk and notify the central processing unit through other interfaces.

8. A method for reading and writing data of a disk data backup system is characterized by comprising the following steps: