How to use the command bmaptool (with examples)
bmaptool is a command-line tool used to create or copy block maps intelligently. It is designed to be faster than the traditional methods of using cp or dd for file copying. The tool is mainly used for faster and efficient copying of image files while preserving the block map information.
Use case 1: Create a blockmap from image file
Code:
bmaptool create -o blockmap.bmap source.img
Motivation:
Creating a blockmap from an image file can be helpful when you want to copy the image file later using the blockmap. By creating a blockmap, you can improve the efficiency of the copying process.
Explanation:
bmaptool: The name of the command-line tool.create: The sub-command used to create a blockmap.-o blockmap.bmap: The option used to specify the output file name for the blockmap. In this case, the blockmap will be saved as “blockmap.bmap”.source.img: The source image file for which the blockmap needs to be created.
Example output:
Created block map file 'blockmap.bmap'.
Use case 2: Copy an image file into sdb using the blockmap
Code:
bmaptool copy --bmap blockmap.bmap source.img /dev/sdb
Motivation:
Copying an image file using the blockmap can provide faster and more efficient copying compared to traditional methods. It utilizes the block map information to optimize the copying process.
Explanation:
bmaptool: The name of the command-line tool.copy: The sub-command used to copy an image file.--bmap blockmap.bmap: The option used to specify the blockmap file to be used for the copying process.source.img: The source image file that needs to be copied./dev/sdb: The destination device where the image file will be copied.
Example output:
Copying image file 'source.img' to '/dev/sdb' using block map file 'blockmap.bmap'.
Finished copying.
Use case 3: Copy a compressed image file into sdb using the blockmap
Code:
bmaptool copy --bmap blockmap.bmap source.img.gz /dev/sdb
Motivation:
When dealing with compressed image files, it is still possible to utilize the blockmap for efficient copying. By using the blockmap, the tool can determine which blocks need to be copied, resulting in improved performance.
Explanation:
bmaptool: The name of the command-line tool.copy: The sub-command used to copy an image file.--bmap blockmap.bmap: The option used to specify the blockmap file to be used for the copying process.source.img.gz: The compressed source image file that needs to be copied./dev/sdb: The destination device where the image file will be copied.
Example output:
Copying compressed image file 'source.img.gz' to '/dev/sdb' using block map file 'blockmap.bmap'.
Finished copying.
Use case 4: Copy an image file into sdb without using a blockmap
Code:
bmaptool copy --nobmap source.img /dev/sdb
Motivation:
In some cases, you may not have a blockmap available or prefer not to use one. In such scenarios, the --nobmap option allows you to copy the image file without utilizing a blockmap.
Explanation:
bmaptool: The name of the command-line tool.copy: The sub-command used to copy an image file.--nobmap: The option used to copy the image file without using a blockmap.source.img: The source image file that needs to be copied./dev/sdb: The destination device where the image file will be copied.
Example output:
Copying image file 'source.img' to '/dev/sdb'.
Finished copying.
Conclusion:
bmaptool is a versatile command-line tool that provides efficient methods for creating and copying block maps. By utilizing blockmaps, users can achieve faster and more optimized copying of image files, resulting in improved performance. Whether it’s creating a blockmap from an image file or copying image files using a blockmap, bmaptool provides a reliable solution for efficient data transfer.
