GB2357604A

GB2357604A - Cloning computer file system using bitmap file

Info

Publication number: GB2357604A
Application number: GB9930633A
Authority: GB
Inventors: Tong S Chen; Kuang-Shin Lin; Hai-Hong Zhang
Original assignee: Inventec Corp
Current assignee: Inventec Corp
Priority date: 1999-12-24
Filing date: 1999-12-24
Publication date: 2001-06-27
Anticipated expiration: 2019-12-24
Also published as: GB9930633D0; GB2357604B

Abstract

A method of cloning a file system of a window web operation system using a bitmap file, includes the steps of (i) storing file data from a source partition in a bitmap file, (ii) compressing the data of the source partition into an image file and cloning the image file to an object disk, (iii) decompressing the compressed bitmap file of the source partition in an object partition in the object disk, enabling decompressed data to be resumed to the object partition, and (iv) modifying the bitmap file subject to the size of the object partition and the physical parameters of the object disk.

Description

2357604 METHOD OF CLONING FILE SYSTEM OF WINDOW WEB OPERATION SYSTEM BY

BITMAP FILE The present invention relates to a method of cloning file system of window web operation system by,bitmap file, and more particularly to the method of cloning file system by bitmap file under Microsoft Window NT operation system.

Clone techniques are intensively used in mass production operation in computer production lines. These techniques commonly make OS (Operation System) and Source File System Partition (hereinafter called as Source Partition) into a compressed file, then clone the compressed file onto every object disk, and then decompress the file, so as to produce object disks identical to original Source Partition. These clone techniques greatly improve computer mass production efficiency. Further, conventional file clone techniques can also be applied to the preparation of a computer system copy for use to resume the system when the computer system fails. Conventionally, file clone techniques adopt a regular procedure to compress file data in proper order. This operation speed is slow. Recently, there is developed a file clone technique, which, as shown in Figure 1, compresses files rapidly without being in conformity with the order of the files. However, under Microsoft's NT Operation System, this file clone technique is based on File System. This technique compresses the content of the source partition subject to a Master File Table (hereinafter called as MFT), forming an Image File, and then decompresses the file after having been cloned to every object disk. During this process, the system inspects all information in the table of content and finds out all files in the source partition, and modifies MFT in the object partition subject to the information of the size and partition condition of the object disk. Because NT File system (hereinafter called as NTFS) records file information in multiple addresses, a new partition cloned by means of the aforesaid file clone technique shows different file information at different addresses when the size of source partition and the size of the object disk are different. This difference destroy the stability of unity of the system, causing file clone operation unaible to be proceeded, or even causing the partition to be crashed. Furthermore, the operation procedure of this file clone technique is complicated and slow, and weak in system protection.

The present invention has been accomplished to provide a file system clone technique, which eliminates the aforesaid drawbacks. The file system clone technique of the invention is to clone data but not the file, therefore it is not necessary to re-build 2 MFT in the object partition, so that the safety and unity of the system are ensured. The method of the present invention greatly increases file clone speed. The advantages of the present invention become more significant when the size of the source partition and the size of the object disk are ildifferent. According to one aspect of the present invention, the file system cloning method uses a bitmap file to clone NT file system. During data cloning process, little file is changed, and itAs not necessary to re build object partition MFT. Further, data access is directly made without through the file system. Therefore, the file system cloning speed is high. According to another aspect of the present invention, the file system cloning method needs not to re-construct object partition MFT, therefore the procedure does not modify file recording information in the partition, and the safety and unity of NT file system are ensured. According to still another aspect of the present invention, the operation procedure of the file system cloning method of the present invention is simple, and a user can easily complete the clone of a NT file system without knowing the system internal structure.

The invention will now be described further by way of example with reference to the accompanying drawings in which:

Figure 1 is a schematic drawing explaining the operation of the prior art file system clone technique.

Figure 2 is a schematic drawing explaining the operation of 3 the file system clone technique of to the present invention.

Figure 3 illustrates the operation architecture of the present invention.

Figure 4 is a flow chart explaining the procedure of making 5 an image file according to the present invention.

Figure 5 is a flow chart explaining the procedure of finding bitmap file according to the present invention.

Figure 6 is a schematic drawing showing the compression process architecture according to the present invention.

Figure 7 is a flow chart explaining the procedure of decompressing bitmap file to object partition according to the present invention.

Figure 8 is a flow chart explaining the procedure of modifying bitmap file.

Referring to Figure 2, data from Source Partition 2 is stored in Bitmap File (Bitmap Table) 1 in the form of Data Block, and then Data Block of Source Partition 2 is compressed into Image File 3 subject to Bitmap File 1. After Image File 3 has been duplicated onto target disk, compressed Bitmap File 1 of Source Partition 2 is decompressed in Object Partition 4 in Object disk. and then Bitmap File 1 is modified to fit size variation from Source 4 Partition 2 to Object Partition 4 subject to the size of Object Partition and physical parameters of Object I)isk.

The clone technique of the invention is to clone File System of Source Partition 2 to Object Partition 4 by Bitmap File 1, enabling the data in Object Partition 4 be maintained in conformity with the data in Source Partition 2 after, decompression. The clone technique includes the following two procedures as shown in Figure 3.

(1) Arrange the data in Source Partition 2, then set up the data into an Image File subject to one Bitmap File of the data, enabling the initial position.of the Image File 3 to be stored in an Image File Header Structure 31, which is stored with certain importance physical parameters of Source Partition 2, such as total sectors, partition information, etc.

(2) Read out the Image File 3 and resume storage data to the Object Partition 4 of one Object Disk. During reading, it reads the parameters in the Image File Header Structure 31 first, then compares the size of the Source Partition 2 with the Object Partition 4, and then modifies the Bitmap File and the related parameters subject to the size of the Object Partition 4, and then write the modified data into the Object Partition 4, and then clones the content of the data block of the Source Partition 2 to the Object Partition 4 of the Object Disk.

Because the Bitmap File is the file existed in file system partition, equivalent to FAT table of FAT format, when searching the address of Bitmap File, as shown in Figure 4, it obtains the position of MFT Table from Boot sector of Source Partition (401), then searches the record of Bitmap File from the first 20 records in NIFT Table (402) to find the physical address and size of Bitmap File from the records (403), so as to obtain the actual address and size of Bitmap File, and the useful data can thus be read out from Source Partition, preventing useless data to appear in Image File, so that the size of Image File can be minimized to improve hard disk clone speed.

When making Image File, as shown in Figure 5, it reads in the data in the first sector from Source Partition (501), then initializes Parameter Block of BIOS parameters (502), and then writes Parameter Block into Boot in Source Partition (503), and then writes file system data into Bitmap File (504), and then reads in Bitmap file and stores it in Temporary File in Buffer (505), and then judges if Bitmap File reading action has been terminated (506)? If Bitmap File has all been read out, it changes the largest cluster number from file data to the smallest sector number (507), then writes the rest data of Bitmap File into Buffer (508), and then returns to the step of reading sector data from Source Partition. If 6 Bitmap File reading action continues, it reads one data block from Bitmap File subject to record number (509), then writes the corresponding cluster number in Image File subject to data message in the data block (510), and then adds the record number of the data block, and then records the largest useful data cluster number (512), and then returns to the step of reading sector data from Source Partition. 1 The invention divides all useful data in Source Partition into several Data Blocks, as illustrated in Figure 6, and then compresses every Data Block, and then stores compressed data of every Data Block into Image File. This procedure enables the size of Image File to be minimized.

When cloning File System from Source Partition to Object Partition, Image File is decompressed, and then Bitmap File of Source Partition is modified subject to the s,ize of Object Partition. The decompression processing procedure is shown in Figure 7. When proceeding to the decompression processing procedure, it reads Image File Header Structure of Image File (701), which is stored with certain importance physical parameters of Source Partition 2 that describe the characteristics of Source Partition such as total sectors, partition information, etc. Then, it proceeds to the step of setting the value of "n" subject to the number of data blocks in Image File (702), and then the step of judging if the set C1 7 value 'V' surpasses zero or not (703)? If the answer is positive, it reads the data from the corresponding Data Block (704), and then judges Data Type of the data (705). If the data is of Boot data (706), it immediately modifies the BIOS Parameter Block of Object Partition (707), and then reserves modified result (708). If the data is of Boot C data (709), File System data (710), or regular data (711), it writes the data, which contains Partition message, write-in address and data content, etc., and reserved Parameter Block into data sector of Object Partition (712), and then it sets Data Block number n=n-1, and then ends off data processing (713), and then repeats the aforesaid processing procedure to read Image File Header Structure of Image File again. The data decompression processing procedure is terminated until the content of all Data Blocks of Image File has been completely processed (i.e., n: 0).

is Bitmap File modification includes the following three modification conditions subject to the size of Object Partition obtained.

(1) When Object Partition Source Partition, it simply sets a Bitmap File end sign in original Bitmap File at the position which represents end of Object Partition.

(2) When Object Partition > Source Partition and original Bitmap File represents the position of end of Object Partition, it clears all redundant data before end of Object Partition, and 8 then sets a Bitmap File end sign at the position of end of Object Partition.

(3) When Object Partition > Source Partition but original Bitmap File does not represent the position of end of Object Partition, it finds a new position in Object Partition and then sets a new Bitmap File, and then clones the content of original Bitmap File to the new position, and then clears all redundant data before end of Object Partition, and then sets a Bitmap File end sign in the position of end of Object Partition.

When modifying Bitmap File, as shown in Figure 8, it judges if Object Partition > Source Partition ($01)? When Object Partition:-js: Source Partition, it sets a File end sign in the original Bitmap File (802);when Object Partition > Source Partition, it judges if Bitmap File of Source Partition can represent Bitmap File end sign of Object Partition or noC, so as to clear from original Bitmap File all redundant data before File end sign (804) in case the answer is positive; if Bitmap File of Source Partition cannot represent Bitmap File end fign of Object Partition, it finds a new Bitmap File position and clones Bitmap File of Source Partition to the new Bitmap File position, and then clears redundant data and sets a File end sign (805).

In an application example of the present invention, the size of Source Partition is 200Mb (Megabyte), and it is divided into 9 400 Data Blocks including.100 useful Data Blocks. When making Image File, Boot sector data is written into Image File, and at last, important physical parameters in Source Partition such as Total Sectors, Partition Information, etc., are written into Image File 5 Header Structure, and thus Image File is done.

In the aforesaid application example, if the size of Object Partition is 150Mb when resuming Source Partition File to Object Partition, it reads the total number of Data Blocks from Image File Header Structure of Image File, then resumes in proper order Boot sector data and the data of 100 Data Blocks and Bitmap File, and then sets Partition End Sign at 150M; if the size of Object Partition is 300Mb, it sets Partition End Sign at 300Mb, and clear from Bitmap File redundant data between 200Mb and 300Mb.

It is to be understood that the drawings are designed for purposes of illustration only, and are not intended for use as a definition of the limits and scope of the invention disclosed.

Claims

1. A method of cloning file system of window web operation system by bitmap file, comprising!the steps of (i) storing file data from a source partition in a bitmap file, (ii) compressing the data of the source partition into an image file and cloning the image file to an object disk, (iii) decompressing the compressed bitmap file of the source partition in an object partition in the object disk, enabling decompressed data to be resumed to the object partition, and (iv) modifying the bitmap file subject to the size of the object partition and the physical parameters of the object disk.

2. The method of claim 1 wherein when storing file data from said source partition in said bitmap file, the position of MFT Table is found from boot sector of said source partition, and then the first 20 records in the MFT Table is searched, so as to find the physical address and size of the bitmap file from the records, and to further obtain the actual address and size of the bitmap file.

3. The method of claim 1 wherein all useful data in said source partition is divided into a plurality of data blocks, and then the data in each data block is compressed, and then compressed data is decompressed and stored in the image file.

4. The method of claim 3 wherein when making the image file, it first reads data in first sector from Source Partition, then initializes Parameter Block of BIOS parameters, and then writes 11 Parameter Block into Boot in Source Partition, and then writes file system data into Bitmap File, and then reads in Bitmap file and stores it to Temporary File in Buffer, and then judges if B itmap File reading action has been terminated, so as to change the largest cluster number from file data to the smallest sector number and write the rest data of Bitmap File into Buffer if Bitmap File has all been read out, and then return to the step of reading sector data from Source Partition.

5. The method of claim 4 wherein if Bitmap File reading action continues when making the image, it reads one data block from Bitmap File subject to record number, then writes the corres onding cluster number in Image File subject to data message p c in the data block, and then adds the record number of the data block, and then records the largest useful data cluster number, and then returns to the step of reading sector data from Source Partition.

6. The method of claim 1 wherein the initial address is stored in a file header structure, which is stored with physical parameters including total number of sectors and partition information.

7. The method of claim 6 wherein when decompressing the image file, it reads parameters of Image File Header Structure of Image File, and then compares the size of the source partition with the object partition, and then modifies the bitmap file and the 12 related parameters subject to the comparison result, and then writes the modified data into the object partition, and then clones the content of the data blocks of the source partition to the object partition of the object disk.

8. The method of claim 7 wherein when cloning file system from the source partition to the object partition, it proceeds to the step of setting the value of "n" subject to the number of data blocks in the image file, and then the step of judging if the set value "n" surpasses zero or not, so as to read the data from the corresponding data block and then judges the data type of the data if the set value GW' surpasses zero, and then to modify the BIOS parameter block of the object partition and reserve the modified result if the data is of Boot data, or to write the data and the revered parameter block into the data sector of the object partition if the data is of file system data or regular data, and then it returns to the step of reading the data of the image file header structure and repeating the procedure until the content of all data blocks of the, image file has been completely processed, i.e. n <- 0.

9. The method of claim 1 wherein when the object partition the source partition, it sets a Bitmap File end sign in original Bitmap File at the position which represents end of Object Partition to end off the modification of the bitmap file.

10. The method of claim 1 wherein when the object 13 partition is greater than the object partition and the original bitmap file represents the position of the end of the object partition, it clears all redundant data before the end of the object partition, and then sets a bitmap file end sign at the position of the end of the 5 object partition to end off the modification of the bitmap file.

11. The method of claim 1 wherein when the object partition is greater than the source partition but the original bitmap file does not represent the position of the end of the object partition, it finds a new position in the object partition and then produces a new bitmap at the new position found, and then clones the content of the original object partition, and then sets a bitmap file end sign at the position of the end of the object partition to end off the modification of the bitmap file.

12. A method of cloning a file system of a window web operation system by bitmap file substantially as herein described with reference to and as illustrated in any one of Figs. 2 to 8 of the accompanying drawings.

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