btrfs-image - create/restore an image of the filesystem
btrfs-image [options] <source> <target>
btrfs-image is used to create an image of a btrfs filesystem. All data will be zeroed, but metadata and the like is preserved. Mainly used for debugging purposes. In the dump mode, source is the btrfs device/file and target is the output file (use - for stdout). In the restore mode (option -r), source is the dumped image and target is the btrfs device/file.
-r Restore metadump image. By default, this fixes super's chunk tree, by using 1 stripe pointing to primary device, so that file system can be restored by running tree log reply if possible. To restore without changing number of stripes in chunk tree check -o option. -c <value> Compression level (0 ~ 9). -t <value> Number of threads (1 ~ 32) to be used to process the image dump or restore. -o Use the old restore method, this does not fixup the chunk tree so the restored file system will not be able to be mounted. -s Sanitize the file names when generating the image. One -s means just generate random garbage, which means that the directory indexes won't match up since the hashes won't match with the garbage filenames. Using -ss will calculate a collision for the filename so that the hashes match, and if it can't calculate a collision then it will just generate garbage. The collision calculator is very time and CPU intensive so only use it if you are having problems with your file system tree and need to have it mostly working. -w Walk all the trees manually and copy any blocks that are referenced. Use this option if your extent tree is corrupted to make sure that all of the metadata is captured. -m Restore for multiple devices, more than 1 device should be provided.
btrfs-image will return 0 if no error happened. If any problems happened, 1 will be returned.
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.