> On Thu, 2007-05-17 at 18:11 +0200, Jan Kara wrote: > > But me (and several other people > > independently as I've learnt recently) have written some tools which > > should result in something useful. If you're interested, you can join > > prefetch-devel@xxxxxxxxxxxxxxxx - it's led by one guy who is doing > > defrag and stuff as his google summer of code project. > > Is this different from the ext4/extent-based defrag patch that's been > mentioned on this list? Yes, it is different. In particular, it's offline only tool so far... > > > *An implementation of an ext* filesystem driver can work with any > > > ext2/3/4 filesystem as long as it supports the necessary revision > > > (GOOD_OLD_REV or DYNAMIC_REV) and feature flags set in the filesystem. > > Not sure what you mean here... > > The "ext2 filesystem"/"ext3 filesystem"/"ext4 filesystem" terminology > was confusing to me when I first started reading about them. In my mind, > it implied that those three filesystems were more different than they > actually are. > > I think it would be more accurate to say that they are all essentially > the same filesystem, and that any filesystem driver that can mount a > given filesystem can mount any other ext2/3/4 filesystem of the same > revision with the same feature flags set. > > I was asking for confirmation of this assumption, but I've since found a > lot of really good documentation that has cleared up a lot of things. Yes, basically it's just a question of a feature set. But for example current online defrag from Takashi requires extents, which are not available for ext2 or ext3. Honza -- Jan Kara <jack@xxxxxxx> SuSE CR Labs - 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
