On Mon, Jul 28, 2008 at 08:49:18AM +1000, Shehjar Tikoo wrote: > Hi Ted > > Theodore Tso wrote: >> The btrfs filesystem effort is an attempt to create a filesystem that >> will leapfrog the ZFS feature set, but it will probably take longer to >> reach production ready status than ext4. > > Since you mention btrfs here and since I've read this earlier too, do > you know if btrfs will be the default Linux file system in the future, > like extX has been? The nature of Linux is such that these sorts of decisions are not made by anyone other than each individual system administrator, and by the distributions who choose which filesystem they which to use as the "default". There is no such thing as an "official" default filesystem. For example, the Maemo distribution, which Nokia distributes for use on the N800/N810 devices, uses jffs2 as its default filesystem, since those devices use a flash storage device. DragonLinux, which is designed to be installed on top of DOS/Windows uses UMSDOS as its default distribution. What happens in the future, who can say? At some point the ext2/3/4 filesystem, which is based fundamentally on a BSD Fast Filesystem design base, may get displaced by a filesystem which uses some very different design as a starting point, when the advantages of starting with that different design outweighs the advantages of backwards compatibility and broad base of support which is enjoyed by ext2/3/4. To give one example from the past, filesystems like JFS were theoretically better than ext3 at the time, but unfortunately all of the expertise was concentrated in one company (IBM), and so distributions were slow to accept it. In the meantime, ext3 was able to add enough features (htree directories, better SMP scalability) to eventually meet and then surpass JFS's technical advantages. XFS has a number of technical advantages over ext3, but the number of people who understand it are small, and people seem to like the tools built for ext3 --- and now ext4 has a number of features that were previously exclusive to XFS. XFS is still the best filesystem for very large, SGI-class machines, however. But for general purpose computing, most people are more comfortable with ext3. Yet the fact that we are retaining backwards compatibility with ext3 does constraint our ability to add radical new features. So eventually some filesystem will probably overtake ext2/3/4. Will that btrfs? I don't think anyone can answer that question. I *have* been helping out the btrfs design team, though, giving them advice such as making sure that they try to gather contributors from a wide variety of distributions and other Linux companies. So I hope they do become successful. In the meantime, though, ext4 is a great extension to the ext2/3 filesystem family. But in the long run, it may very well be that btrfs will be more successful than some future attempt to create an ext5; and that's fine. Regards, - 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
