On Sun, Jul 17, 2016 at 3:08 AM, Hendrik Friedel <hendrik@xxxxxxxxxxxxx> wrote: > Well, btrfs does write data very different to many other file systems. On > every write the file is copied to another place, even if just one bit is > changed. That's special and I am wondering whether that could cause > problems. It depends on the application. In practice, the program most responsible for writing the file often does a faux-COW by writing a whole new (temporary) file somewhere, when that operation completes, it then deletes the original, and move+renames the temporary one into place where the original one, doing fsync in between each of those operations. I think some of this is done via VFS also. It's all much more metadata centric than what Btrfs would do on its own. I'd expect the write pattern of Btrfs to be similar to f2fs, with respect to sequentiality of new writes. -- Chris Murphy -- 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
