CN103268269A - Data Recovery Method of RAID-5 - Google Patents

Abstract

The invention provides a data recovery method for RAID-5 (redundant array of independent disks 5). The method includes: acquiring a MBR (master boot record); judging whether a file record number exists or not; if not, acquiring an SSN (strip size number), and according to the MBR, acquiring an SSS (strip starting sector), left-right structure of disks, disk sequence, synchronous and asynchronous conditions of the disks, and a data starting sector BSN; and performing data recovery according to the SSN, the SSS, the left-right structure of disks, the disk sequence, the synchronous and asynchronous conditions of the disks, and the data darting sector BSN. The method has the advantages that RAID information of the RAID-5 can be analyzed accurately and data is recovered with the RAID information while no file record number exists in an NTFS (new technology file system), and accordingly the problems of low accuracy, low success rate and poor universality in the existing RAID-5 data recovery method are solved.

Description

Data Recovery Method of RAID-5

technical field

The present invention relates to the field of data recovery, in particular, to a RAID-5 data recovery method.

Background technique

Redundant Array of Independent Disks (RAID) refers to combining multiple physical disk drives into a large-capacity virtual disk drive in hardware or software through a RAID controller. The basic principle of RAID is to use Bit Striping (Bit Striping) and the current mainstream Block Striping (Block Striping) segmentation method to disperse and store the same data into different data blocks (Data Blocks) in each disk drive. When the data block of the disk drive is damaged, the XOR operation is used to compare and calculate the parity disk segments (Parity Blocks) and the data in the data block stored in other disk drives to reconstruct (Rebuild) the damaged data .

When data is stored in RAID, data storage is performed by multiple read-write heads on multiple physical disk drives. Therefore, not only the speed of writing data is very fast, but also because the same data is stored in multiple physical disk drives. For different data block positions in the drive, RAID also has data fault tolerance function, which provides better security guarantee for data storage.

Currently, commonly used RAID mainly includes RAID-0, RAID-1, RAID-1E, RAID-5, RAID-6, RAID-7, RAID-10, RAID-50, etc. Among them, RAID-5 is the most widely used because it takes into account storage performance, data security, and storage cost.

However, when the RAID controller of RAID-5 has a physical failure and causes RAID information to be wrong or configuration information is lost due to human misoperation, the RAID-5 logical disk will be lost or inaccessible. Once the above situation occurs, it will lead to the loss and damage of disk data, and the loss is often quite serious. In the above cases, data recovery for RAID-5 is required. The key point of data recovery is to analyze the RAID structure to obtain RAID information. Once the RAID information is recovered, read the data in the disk according to the information, so as to achieve the data recovery of RAID-5.

At present, most of the servers using the Windows operating system use the NTFS file system. The recovery of RAID-5 data under the NTFS file system is mainly to use some tools for manual recovery. Information recovery, but this method is accidental and highly professional, and does not have universal applicability. In addition, there are also software to analyze the RAID structure, such as RAID Reconstructor, but the accuracy rate of this type of software for RAID structure analysis is extremely low, resulting in a low success rate of data recovery. In addition, it is also possible to analyze the RAID information through the file record number, and then perform data recovery through the RAID information, but it cannot be operated without the file record number in the NTFS file system.

Contents of the invention

The technical problem to be solved by the present invention is to provide a data recovery method of RAID-5. Under the situation that the NTFS file system does not have a file record number, the RAID information of RAID-5 can be accurately analyzed, and data recovery can be performed using the RAID information. , to solve the problems of low accuracy, low success rate and poor universality of existing RAID-5 data recovery methods.

The present invention proposes a data recovery method of RAID-5, comprising:

Get the master boot record MBR;

Determine whether there is a file record number;

If the judgment result is no, then obtain the stripe size SSN, and obtain the stripe start sector SSS, the left and right structure of the disk, the disk sequence, the synchronization and asynchronous situation of the disk and the data start sector BSN according to the MBR;

Data recovery is performed according to the SSN, SSS, left and right structure of the disk, disk sequence, synchronous and asynchronous conditions of the disk, and BSN.

Further, the steps for judging whether there is a file record number are specifically as follows:

Obtaining a file record MFT according to the MBR;

Determine whether there is a file record number according to the MFT.

Further, the step of obtaining the stripe start sector SSS according to the MBR is specifically:

Obtain the SN _MBR of the sector where the MBR is located;

Set the stripe start sector to SN _MBR .

Further, the step of obtaining the left and right structures of the disk according to the MBR is specifically:

Judging whether the number of the MBR is 1;

If the judgment result is no, the verified MBR is removed;

If the judgment result is yes, obtain the sector SN where any verification information of the disk where the MBR is located;

Obtain the left and right structures of the disk according to the value of (SN-SN _MBR )%(SSN×i)/SSN;

where i is the number of disks.

Further, the steps for obtaining the stripe size SSN are as follows:

Obtain the DOS boot record DBR of the NTFS partition;

Obtain the position judgment value _D1 of the sector where the master file table $MFT is located according to the DBR;

According to the first parameter of the $MFT, obtain the region RMFT with more file record _MFTs ;

Obtain the sector PSn where the verification information P appears for the first time on the nth disk in the _RMFT ;

Obtain the stripe size SSN according to the PSn;

Among them, D ₁ = the sector where the DBR is located + (the starting cluster number of $MFT in the DBR × the number of sectors in each cluster in the DBR) / (i-1);

Wherein, i is the number of disks, 1≤n≤i.

Further, the steps for obtaining the DOS boot record DBR of the NTFS partition are as follows:

According to the hard disk partition table DPT in the MBR, obtain the position judgment value D ₂ of the sector where the DBR is located;

Acquire the location of the sector where the DBR is located according to the decision value _D2 ;

Among them, D ₂ = number of hidden sectors of SN _MBR + NFTS partition in MBR / (i-1).

Further, the step of obtaining the disk sequence according to the MBR is specifically:

Obtain the disk sequence according to the value of (PSn- SN _MBR )%(SSN×i).

Further, the steps for obtaining the synchronous and asynchronous conditions of the disk according to the MBR are as follows:

Obtain the sector where the end position of the MFT data stream is located according to the disk sequence, the stripe start sector, and the first parameter of $MFT;

According to the sector where the end position of the MFT data stream is located, it is judged whether the synchronous and asynchronous situation of the disk can be obtained;

If the judgment result is yes, the synchronous and asynchronous conditions of the disk are obtained according to the sector where the end position of the MFT data stream is located.

Further, the method of the present invention also includes:

When it is judged that the asynchronous situation of the disk cannot be obtained according to the sector where the MFT data stream end position is located, the following steps are performed to obtain the asynchronous situation of the disk:

Assume that the disk is synchronous, and judge whether the file suffix name of the second parameter of the MFT matches the data signature header of the first parameter of $MFT;

If the judgment result is no, it is judged that the disk is asynchronous;

If the judgment result is yes, it is assumed that the disk is asynchronous, and it is judged whether the file suffix name of the second parameter of the MFT matches the data signature header of the first parameter;

If the judgment result is no, it is judged that the disk is synchronous;

If the judgment result is yes, the next MFT is obtained and the above steps are repeated until the correct disk synchronization and asynchronous conditions are obtained or the MFT cannot be obtained.

Further, the steps of obtaining the data start sector BSN are specifically:

Set data start sector BSN to 0.

Further, before obtaining the master boot record MBR, the following steps are also included:

Search the disk for the Master Boot Record MBR.

Further, if the MBR is not found, the SSN, SSS, the left and right structure of the disk, the disk sequence, the synchronous and asynchronous conditions of the disk and the BSN are obtained through the following steps, wherein:

The steps for obtaining the SSN are as follows:

Obtain the DOS boot record DBR of the NTFS partition;

Obtain the position judgment value _D1 of the sector where the master file table $MFT is located according to the DBR;

According to the first parameter of the $MFT, obtain the region RMFT with more file record _MFTs ;

Obtain the sector PSn where the verification information P appears for the first time on the nth disk in the _RMFT ;

Obtain the stripe size SSN according to the PSn;

Among them, D ₁ = the sector where the DBR is located + (the starting cluster number of $MFT in the DBR × the number of sectors in each cluster in the DBR) / (i-1);

The steps for obtaining the SSS are as follows:

Determine whether RAID-5 is composed of dynamic disks;

If the judgment result is yes, set the stripe start sector to the start of the first NTFS file system partition

the sector in which it is located;

If the judgment result is no, set SSS to 0;

The steps for obtaining the disk sequence, left-right structure, and synchronous and asynchronous conditions of the disk are as follows:

Obtain the disk sequence of the disk according to the value of PSn%(SSN×i)/SSN;

Obtain the sector where the MFT data stream ends according to the first parameter of the $MFT;

According to the sector where the end position of the MFT data stream is located, it is judged whether the left and right structure and the synchronous and asynchronous situation of the disk can be obtained;

If the judgment result is yes, then obtain the disk left and right structure and synchronous and asynchronous situation according to the sector where the end position of the MFT data stream is located; Whether the file suffix name of the second parameter matches the data characteristic header of the first parameter of $MFT, and obtain the correct left and right disk structure and synchronous and asynchronous conditions;

If the judgment result is no, then according to the situation of whether the file suffix name of the second parameter of the MFT matches the data characteristic head of the first parameter, obtain the correct left and right disk structure and synchronous asynchronous situation;

The specific steps for obtaining the BSN are as follows:

If the disk is a right structure, then judge whether (the sector where the DBR is located-SSS)%(SSN×i)/SSN is equal to the disk sequence of the disk where the DBR is located;

If the judgment result is yes, the DBR is a checked DBR and eliminated;

If the judgment result is no, the number of sectors hidden in the DBR is the BSN;

If the disk is of the left structure, then judge whether (the sector where the DBR is located-SSS)%(SSN×i)/SSN is equal to the disk sequence of the disk where the N-DBR is located-1;

If the judgment result is yes, the DBR is a checked DBR and eliminated;

If the judgment result is no, the number of sectors hidden in the DBR is the BSN;

Wherein, i is the number of disks, 1≤n≤i.

The embodiment of the data recovery method of RAID-5 provided by the present invention can accurately analyze the RAID information of RAID-5 under the situation that the NTFS file system has no file record number, and use the RAID information to perform data recovery to solve the problem There are the problems of low accuracy rate, low success rate and poor universality of the RAID-5 data recovery method.

Description of drawings

Fig. 1 is the flowchart of the first embodiment of the data recovery method of RAID-5 of the present invention;

Fig. 2 is the flow chart of obtaining the left and right structures of the disk according to the MBR in the second embodiment of the data recovery method of RAID-5 of the present invention;

Fig. 3 is the flow chart that obtains the synchronous and asynchronous situation of disk according to MBR in the data restoration method of RAID-5 of the present invention second embodiment;

Fig. 4 is the flow chart of obtaining SSS in the third embodiment of the data recovery method of RAID-5 of the present invention;

FIG. 5 is a flow chart of obtaining the left-right structure and synchronous and asynchronous conditions of the disk in the third embodiment of the RAID-5 data recovery method of the present invention.

Detailed ways

In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

With reference to Fig. 1, show the flow chart of the first embodiment of the data recovery method of RAID-5 of the present invention, comprise the steps:

S1, acquiring a master boot record MBR.

S2, judging whether there is a file record number. If the judgment result is no, that is, there is no file record number, then go to S3.

S3, if there is no file record number, obtain the stripe size SSN, and obtain the stripe start sector SSS, the left and right structure of the disk, the disk sequence, the synchronization and asynchrony of the disk, and the data start sector BSN according to the MBR.

S4. Perform data recovery according to the SSN, SSS, left and right structure of the disk, disk sequence, synchronization and asynchronous conditions of the disk, and BSN.

According to the first embodiment of the data recovery method of RAID-5 of the present invention, it can be realized that when the NTFS file system does not have a file record number, the RAID information of RAID-5 can be accurately analyzed, and data recovery can be performed using the RAID information, wherein The RAID information includes the stripe size SSN, the stripe start sector SSS, the left and right structure of the disk, the disk sequence, the synchronization and asynchronous conditions of the disk, and the data start sector BSN. The first embodiment of the method not only has strong universality, And it has high recovery accuracy and recovery success rate.

Further, the second embodiment of the RAID-5 data recovery method provided by the present invention is an improvement on the basis of the first embodiment of the above method, wherein the step of obtaining the stripe size SSN in S3 is specifically:

S11, according to the DBR characteristics of the NTFS partition, search for the DOS boot record DBR in the disk in sequence and obtain the DOS boot record DBR.

Wherein, the DBR includes location information and record information of the DBR, the location information of the DBR includes the sector where the DBR is located, etc., and the record information of the DBR includes the starting cluster number of $MFT in the DBR and the number of sectors of each cluster in the DBR, etc.

S12. According to the DBR, the position determination value D ₁ of the sector where the master file table $MFT is located is obtained, and the sector of the master file table $MFT is located near D ₁ .

Among them, D ₁ = the sector where the DBR is located + (the starting cluster number of $MFT in the DBR × the number of sectors in each cluster in the DBR) / (i-1). Wherein, i in this article represents the number of disks included in RAID-5.

S13. According to the attribute of the first parameter 0x80 of the master file table $MFT, the region _RMFT with more file records MFT is acquired.

S14. Search sequentially in the _RMFT to obtain the sector PSn where the parity information P appears for the first time on the nth disk, where 1≤n≤i.

Among them, the way to determine the sector where the verification information P appears for the first time on the disk is: on this sector, except that the information of the disk is not a file record MFT and is not all 0, the information on other disks are all file records MFT.

S15. Obtain the stripe size SSN according to the PSn.

The acquisition method is specifically as follows: firstly, the PSn with the smallest value is eliminated, and then the tolerance of the remaining PSn is calculated, and the tolerance is the size SSN of the stripe.

Since it cannot be guaranteed that the PSn with the smallest value is the start position of a certain band, in order to obtain the start position of the band more accurately, the PSn with the smallest value is eliminated.

Further, in the second embodiment of the data recovery method of RAID-5, the steps of S11 specifically include:

S111, according to the partition information recorded in the hard disk partition table DPT in the MBR, obtain the position judgment value D ₂ of the sector where the DBR is located, and the sector where the DBR is located is located near D ₂ .

Wherein, D ₂ =the sector where the MBR is located+the number of hidden sectors of the NFTS partition in the MBR/(i-1).

S112. Acquire the location of the sector where the DBR is located according to _D2 .

Further, in the second embodiment of the data recovery method of RAID-5, the step of S2 judging whether there is a file record number is specifically:

S21. Acquire the file record MFT according to the MBR.

S22. Determine whether there is a file record number according to the MFT.

Further, in the second embodiment of the data recovery method of RAID-5, the step of obtaining the stripe start sector SSS according to the MBR is specifically:

S301, obtain the sector SN _MBR where the MBR is located;

S302. Set the start sector of the stripe as the SN _MBR .

Further, referring to FIG. 2, it is a flow chart of obtaining the left and right structures of the disk according to the MBR in the second embodiment of the RAID-5 data recovery method of the present invention, which specifically includes the following steps:

S311. Determine whether the number of MBRs is 1.

If the judgment result is no, go to S312, and if the judgment result is yes, go to S313.

S312. Delete the verified MBR.

Among them, it is judged whether the value of (PSn-SN _MBR )%(i×SSN)/SSN is 0, if it is 0, then the MBR is the verified MBR, if not 0, then it is the real MBR.

S313. Obtain the sector SN where any check information of the disk where the MBR is located is located.

S314. Acquire the left and right structures of the disk according to the value of (SN−SN _MBR )%(SSN×i)/SSN.

Wherein, if the value is equal to 1, the disk is a right structure; if the value is not equal to 1, the disk is a left structure.

Further, in the second embodiment of the data recovery method of RAID-5, the step of obtaining the disk sequence according to the MBR is specifically:

S321. Obtain the disk sequence according to the value of (PSn-SN _MBR )%(SSN×i).

Wherein, if the disk is of the right structure, the value is the disk sequence; if the disk is of the left structure, the disk sequence is opposite to the value.

Further, referring to FIG. 3, it is a flow chart of obtaining the synchronous and asynchronous conditions of the disk according to the MBR in the second embodiment of the RAID-5 data recovery method of the present invention, which specifically includes the following steps:

S331. Obtain the sector where the end position of the MFT data stream is located according to the disk sequence, the stripe start sector, and the data stream information recorded in the first parameter 0x80 of $MFT.

S332, judging whether the synchronization and asynchrony of the disk can be obtained according to the sector where the MFT data stream ends, if the judging result is yes, go to S333.

Among them, the synchronous and asynchronous conditions of the disk that cannot be obtained are as follows: first, the end sector is the end sector of any stripe, and except for the disk where the verification information is located, all other disks on the stripe are MFT; second, in the In the disk sequence, on the stripe where the end sector is located, the disk where the MFT is located is located on one side of the disk where the verification information is located, and the disk where the verification information is located is the first disk or the last disk in the disk sequence.

S333. Obtain the synchronous and asynchronous conditions of the disk according to the sector where the end position of the MFT data stream is located.

Further, when the determination result of S332 is no, the synchronous and asynchronous conditions of the disk are obtained according to the following steps.

If the judgment result of S332 is no, that is, it is judged that the synchronous and asynchronous situation of the disk cannot be obtained according to the sector where the MFT data stream end position is located, then the synchronous and asynchronous situation of the disk is obtained according to the following steps:

S334, assuming that the disk is synchronous, and judging whether the file extension in the second parameter 0x30 of the MFT matches the signature header of the data pointed to by the first parameter 0x80 of $MFT. If the judgment result is no, then go to S335, if the judging structure is yes, then go to S336.

The judgment is made according to the database of the corresponding relationship between the file type and the data characteristic header in the RAID-5 disk. Wherein, when each file type is stored on the disk, the value of the data header, that is, the data characteristic header is fixed, and the data characteristic header corresponds to the file type.

S335. Determine that the disk is asynchronous.

S336, assuming that the disk is asynchronous, and judging whether the file extension in the second parameter 0x30 of the MFT matches the characteristic header of the data pointed to by the first parameter 0x80 of $MFT. If the judgment result is no, then go to S337, if the judgment result is yes, then obtain the next MFT and repeat the above steps to return to S334 until the correct disk synchronization and asynchronous situation is obtained or no MFT can be obtained any more.

S337. Determine that the disk is synchronous.

Further, in the second embodiment of the RAID-5 data recovery method, the step of obtaining the data start sector BSN is specifically: setting the data start sector BSN to 0.

Further, in the second embodiment of the RAID-5 data recovery method, before S1 acquires the master boot record MBR, the following step is further included: searching for the master boot record MBR in the disk according to the characteristic value of the MBR.

Furthermore, the third embodiment of the RAID-5 data recovery method of the present invention will be introduced below. The third embodiment of the method is an improvement on the basis of the second embodiment of the above method.

If the MBR is not found, take the following steps to obtain the stripe size SSN, stripe start sector SSS, disk left and right structure, disk sequence, disk synchronization and asynchronous conditions, and data start sector BSN.

In the third embodiment of the data recovery method of RAID-5, the steps of obtaining the stripe size SSN are specifically:

S501. Search for the DOS boot record DBR in the disk sequentially according to the DBR characteristics of the NTFS partition and acquire the DOS boot record DBR.

Wherein, the DBR includes location information and record information of the DBR, the location information of the DBR includes the sector where the DBR is located, etc., and the record information of the DBR includes the starting cluster number of $MFT in the DBR and the number of sectors of each cluster in the DBR, etc.

S502. According to the DBR, the position judgment value D ₁ of the sector where the master file table $MFT is located is obtained, and the sector of the master file table $MFT is located near D ₁ .

Among them, D ₁ = the sector where the DBR is located + (the starting cluster number of $MFT in the DBR × the number of sectors in each cluster in the DBR) / (i-1). Wherein, i in this article represents the number of disks included in RAID-5.

S503. According to the first parameter 0x80 attribute of the master file table $MFT, acquire the region RMFT with more file record _MFTs .

S504. Search sequentially in the _RMFT to acquire the sector PSn where the parity information P appears for the first time on the nth disk, where 1≤n≤i.

Among them, the way to determine the sector where the verification information P appears for the first time on the disk is: on this sector, except that the information of the disk is not a file record MFT and is not all 0, the information on other disks are all file records MFT.

S505. Acquire the stripe size SSN according to the PSn.

The acquisition method is specifically as follows: firstly, the PSn with the smallest value is eliminated, and then the tolerance of the remaining PSn is calculated, and the tolerance is the size SSN of the stripe.

Since it cannot be guaranteed that the PSn with the smallest value is the start position of a certain band, in order to obtain the start position of the band more accurately, the PSn with the smallest value is eliminated.

Referring to Fig. 4, it is the flowchart of obtaining SSS in the third embodiment of the data recovery method of RAID-5 of the present invention, specifically comprises the following steps:

S511. Determine whether the RAID-5 is composed of dynamic disks. If the result is judged, go to S502; if the result is no, go to S503.

S512, set the stripe start sector as the first file system (for example, FAT, NTFS, etc.)

sector where it starts.

S513, set SSS to 0.

In the third embodiment of the RAID-5 data recovery method of the present invention, the step of obtaining the disk sequence is specifically: obtaining the disk sequence according to the value of PSn%(SSN×i)/SSN.

Among them, if the disk is a right structure, then this value is the disk sequence of the disk. If the disk is a left structure, the disk order of the disk is opposite to this value.

Referring to Fig. 5, it is a flow chart of obtaining the left and right structure of the disk and the synchronous and asynchronous situation in the third embodiment of the data recovery method of RAID-5 of the present invention, specifically comprising the following steps:

S521. Acquire the sector where the end position of the MFT data stream is located according to the disk sequence, the stripe start sector, and the data stream information recorded in the first parameter 0x80 of $MFT.

S522. Determine whether the left-right structure of the disk and the synchronous and asynchronous conditions of the disk can be obtained according to the sector where the end position of the MFT data stream is located. If the judgment result is yes, then go to S523, if the judgment result is no, then go to S524.

Among them, the scenario where the left and right structure of the disk and the synchronous and asynchronous conditions cannot be obtained is as follows: the end sector is the end sector of any stripe, and except for the disk where the verification information is located, all other disks are MFT on the stripe;

S523, obtain the left and right structure and synchronous and asynchronous situation of the disk according to the sector where the MFT data stream end position is located, in the case of failing to obtain the left and right structure and/or the synchronous and asynchronous situation, according to the file suffix name of the second parameter 0x30 of MFT and $MFT Whether the data characteristic head of the first parameter Ox80 matches the situation, obtains the correct disk left and right structure and/or synchronous asynchronous situation.

Among them, in the disk sequence, on the end sector, in the disks before and after the disk where the verification information is located, if there is no MFT on any disk, the synchronous and asynchronous conditions can be judged; specifically, if any of the previous disks If a disk has MFT and the following disk does not have MFT, or the front disks are all MFT, and any of the following disks does not have MFT, it is asynchronous; otherwise, it is synchronous;

In the disk sequence, on the end sector, in the front or back of the disk where the verification information is located, some disks contain MFT, which can determine the left and right structures; specifically, according to the left and right structures, the obtained disk sequence , which is characterized in that the disk with the first disk sequence has MFT, and the disk behind may have MFT. If this characteristic is violated, it proves that the structure is wrong.

S524. According to whether the file suffix name of the second parameter Ox30 of the MFT matches the characteristic header of the data pointed to by the first parameter 0x80 of the $MFT, obtain the correct left and right structure of the disk and the synchronous and asynchronous conditions.

Wherein, if the file suffix name of the second parameter Ox30 of MFT matches the characteristic head of the data pointed to by the first parameter of $MFT, it means that the obtained disk left-right structure and synchronous and asynchronous conditions may be accurate. If the file suffix name of the second parameter Ox30 of MFT does not match the data feature header of the first parameter Ox80 of $MFT, it means that the obtained disk left and right structure and synchronous and asynchronous situation are inaccurate, so it is excluded. When it is ruled out that there is only one left and right structure combined with synchronous and asynchronous or when the MFT cannot be obtained

In the third embodiment of the data recovery method of RAID-5 of the present invention, the steps of obtaining the BSN are specifically:

S531 , in the case that the disk has a right structure, judge whether (the sector where the DBR is located-SSS)%(SSN×i)/SSN is equal to the disk sequence of the disk where the DBR is located. If the judging result is yes, the DBR is a checked DBR and removed; if the judging result is no, the number of hidden sectors in the DBR is set as the BSN.

S532, if the disk is of the left structure, judge whether (the sector where the DBR is located-SSS)%(SSN×i)/SSN is equal to the disk sequence-1 of the disk where the N-DBR is located. If the judgment result is yes, then confirm that the DBR is a verified DBR and remove it; if the judgment result is no, set the number of hidden sectors in the DBR as the BSN.

For the aforementioned method embodiments, for the sake of simple description, they are expressed as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention , some steps can be performed in other orders or simultaneously; secondly, those skilled in the art should also know that the above method embodiments are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other.

The data recovery method of a kind of RAID-5 provided by the present invention has been introduced in detail above. The principles and implementation methods of the present invention have been explained by using specific examples in this paper. The description of the above embodiments is only used to help understand the present invention. method and its core idea; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation and scope of application. In summary, the content of this specification should not be understood as Limitations on the Invention.

Claims (12)

1. A data recovery method of RAID-5, characterized in that, comprising: Get the master boot record MBR; Determine whether there is a file record number; If the judgment result is no, then obtain the stripe size SSN, and obtain the stripe start sector SSS, the left and right structure of the disk, the disk sequence, the synchronization and asynchronous situation of the disk and the data start sector BSN according to the MBR; Data recovery is performed according to the SSN, SSS, left and right structure of the disk, disk sequence, synchronous and asynchronous conditions of the disk, and BSN. 2. The method according to claim 1, wherein the step of judging whether there is a file record number is specifically: Obtaining a file record MFT according to the MBR; Determine whether there is a file record number according to the MFT. 3. The method according to claim 1, wherein the step of obtaining the start sector SSS of a stripe according to the MBR is specifically: Obtain the SN _MBR of the sector where the MBR is located; Set the stripe start sector to SN _MBR . 4. The method according to claim 3, wherein the step of obtaining the left and right structures of the disk according to the MBR is specifically: Judging whether the number of the MBR is 1; If the judgment result is no, the verified MBR is removed; If the judgment result is yes, obtain the sector SN where any verification information of the disk where the MBR is located; Obtain the left and right structures of the disk according to the value of (SN-SN _MBR )%(SSN×i)/SSN; where i is the number of disks. 5. The method according to claim 3, wherein the step of obtaining the stripe size SSN is specifically: Obtain the DOS boot record DBR of the NTFS partition; Obtain the position judgment value _D1 of the sector where the master file table $MFT is located according to the DBR; According to the first parameter of the $MFT, obtain the region RMFT with more file record _MFTs ; Obtain the sector PSn where the verification information P appears for the first time on the nth disk in the _RMFT ; Obtain the stripe size SSN according to the PSn; Among them, D ₁ = the sector where the DBR is located + (the starting cluster number of $MFT in the DBR × the number of sectors in each cluster in the DBR) / (i-1); Wherein, i is the number of disks, 1≤n≤i. 6. the method as claimed in claim 5, is characterized in that, the step of obtaining the DOS boot record DBR of NTFS partition is specifically: According to the hard disk partition table DPT in the MBR, obtain the position judgment value D ₂ of the sector where the DBR is located; Acquire the location of the sector where the DBR is located according to the decision value _D2 ; Wherein, D ₂ =the sector where the MBR is located+the number of hidden sectors of the NFTS partition in the MBR/(i-1). 7. The method according to claim 5, wherein the step of obtaining the disk sequence according to the MBR is specifically: Obtain the disk sequence according to the value of (PSn- SN _MBR )%(SSN×i). 8. The method according to claim 7, wherein the step of obtaining the synchronous and asynchronous conditions of the disk according to the MBR is specifically: Obtain the sector where the end position of the MFT data stream is located according to the disk sequence, the stripe start sector, and the first parameter of $MFT; According to the sector where the end position of the MFT data stream is located, it is judged whether the synchronous and asynchronous situation of the disk can be obtained; If the judgment result is yes, the synchronous and asynchronous conditions of the disk are obtained according to the sector where the end position of the MFT data stream is located. 9. The method of claim 8, further comprising: When judging that the synchronous and asynchronous situation of the disk cannot be obtained according to the sector where the MFT data stream end position is located, the following steps are performed to obtain the synchronous and asynchronous situation of the disk: Assume that the disk is synchronous, and judge whether the file suffix name of the second parameter of the MFT matches the data signature header of the first parameter of $MFT; If the judgment result is no, it is judged that the disk is asynchronous; If the judgment result is yes, it is assumed that the disk is asynchronous, and it is judged whether the file suffix name of the second parameter of the MFT matches the data signature header of the first parameter; If the judgment result is no, it is judged that the disk is synchronous; If the judgment result is yes, the next MFT is obtained and the above steps are repeated until the correct disk synchronization and asynchronous conditions are obtained or the MFT cannot be obtained. 10. The method according to claim 1, wherein the step of obtaining the data start sector BSN is specifically: Set data start sector BSN to 0. 11. The method according to claim 5, further comprising the steps of: Search the disk for the Master Boot Record MBR. 12. The method of claim 11, wherein, In the case that the MBR is not searched, the SSN, SSS, left and right structure of the disk, disk sequence, synchronous and asynchronous situation of the disk and BSN are obtained through the following steps, wherein: The steps for obtaining the SSN are as follows: Obtain the DOS boot record DBR of the NTFS partition; Obtain the position judgment value _D1 of the sector where the master file table $MFT is located according to the DBR; According to the first parameter of the $MFT, obtain the region RMFT with more file record _MFTs ; Obtain the sector PSn where the verification information P appears for the first time on the nth disk in the _RMFT ; Obtain the stripe size SSN according to the PSn; Among them, D ₁ = the sector where the DBR is located + (the starting cluster number of $MFT in the DBR × the number of sectors in each cluster in the DBR) / (i-1); The steps for obtaining the SSS are as follows: Determine whether RAID-5 is composed of dynamic disks; If the judgment result is yes, set the stripe start sector to the start of the first NTFS file system partition the sector in which it is located; If the judgment result is no, set SSS to 0; The steps for obtaining the disk sequence, left and right structure, and synchronous and asynchronous conditions of the disk are as follows: Obtain the disk sequence of the disk according to the value of PSn%(SSN×i)/SSN; Obtain the sector where the MFT data stream ends according to the first parameter of the $MFT; According to the sector where the end position of the MFT data stream is located, it is judged whether the left and right structure and the synchronous and asynchronous situation of the disk can be obtained; If the judgment result is yes, then obtain the disk left and right structure and synchronous and asynchronous situation according to the sector where the end position of the MFT data stream is located; Whether the file suffix name of the second parameter matches the data characteristic header of the first parameter of $MFT, and obtain the correct left and right disk structure and synchronous and asynchronous conditions; If the judgment result is no, then according to the situation of whether the file suffix name of the second parameter of the MFT matches the data characteristic head of the first parameter, obtain the correct left and right disk structure and synchronous asynchronous situation; The specific steps for obtaining the BSN are as follows: If the disk is a right structure, then judge whether (the sector where the DBR is located-SSS)%(SSN×i)/SSN is equal to the disk sequence of the disk where the DBR is located; If the judgment result is yes, the DBR is a checked DBR and eliminated; If the judgment result is no, the number of sectors hidden in the DBR is the BSN; If the disk is of the left structure, judge whether (the sector where the DBR is located-SSS)%(SSN×i)/SSN is equal to the disk sequence of the disk where the N-DBR is located-1; If the judgment result is yes, the DBR is a checked DBR and is eliminated; If the judgment result is no, the number of sectors hidden in the DBR is the BSN; Wherein, i is the number of disks, 1≤n≤i.

Images