On Wed, Jul 15, 2015 at 11:20:55AM -0400, Austin S Hemmelgarn wrote: > > There really isn't much of a clear distinction between ext3 and ext4 (at > least from an end user standpoint), other than the fact that there are some > options that only the ext4 driver understands (like extent based > allocation). Yeah, the main reason why we did the ext3 -> ext4 fork was that adding 64-bit numbers required major surgery, and we didn't want to break a lot of production users who were using ext3. But from a file system format perspective, ext2, ext3, and ext4 are the same logical file system. There are just multiple different implementations, which all support slightly different sets of file system features: * Linux's ext2 * Linux's ext3 * Linux's ext4 * Hurd's ext2 * *BSD's ext2 * Grub's ext2/3/4 The last three implementations are in fact independent ones created from scratch. :-) Fortunately we use the same file system support code, e2fsprogs, for all of them, which is good since it has a very extensive set of regression test sets for our fsck program, and we've continued adding to it as we add new file system features. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
