Hi Ryusuke, On Friday 03 June 2011 19:26:21 you wrote: > (...) > NILFS2 is a log-structured filesystem and that means the filesystem > itself is a big journal. My understanding is using separate journal > device has no merit of performance. > > On the other hand, We may be able to speed up the filesystem by > putting DAT (disk address translation) metadata to a separate device. > I mean putting a full copy of the DAT metadata on the sperate device > instead of journal of it. *nods* sounds interesting. Of course changing on-disk format would hurt ;-) > But, I think we have other approaches to think about before that with > regard to performance improvement. For example, applying "extent" to > DAT seems much more effective. Currently every block of file gets own entry in DAT, right? By the way, it seems to me that the in-kernel GC does not attempt to de- fragment files. Is that the case? If so, would probably mean extents would not help very much for fragmented files. Also, on magnetic media, a lot of seeking happens in case of fragmented files. Regards, -- dexen deVries ``One can't proceed from the informal to the formal by formal means.'' -- To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
