Hello, I'm currently trying to understand how compression in btrfs works. I could not find any detailed description about it. So here are my questions. 1. How is decided what to compress and what not? After a fast test with a 2g image file, I've looked into the extents of that file with find-new and it turned out that only some of the first extents were compressed. The file was simply copied with cp. 2. I compared the extents of that mentioned file from a non-compressed fs and from a compressed fs and see much more and much smaller extents in the compressed fs. Does compression affect extent allocation or is this just a coincidence? The source file was in use (VirtualBox was running) while I was copying it...if this has too much influence on extent allocation then please ignore the whole question. 3. How large are the blocks that get compressed? If it's dynamic, how is decided which size to use? 4. If there is no maximum on compressed extents size, is the whole extent compressed at once or in blocks? More questions may follow... Alex. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
