Stephen C. Tweedie writes: > Hi, > > On Fri, Jan 18, 2002 at 01:23:11PM +0000, Zoiah wrote: > >> I see in your benchmark that EXT3 is actually performing better than EXT2. >> How is that possible? Because as far as I know EXT3 is just EXT2 + >> journalling which means more work for the HD. > > It depends very much on the workload. ext3 can often avoid seeks that > ext2 has to do, because it can flush data out sequentially to the > journal rather than having to seek to all the bitmap and inode blocks > when writing out a change to disk. This is especially noticeable with > some synchronised-IO benchmarks, where ext2 has to seek all over the > disk for every IO request, whereas ext3 can just append a bit more to > the journal. So, simply put, you can see the journal as a small on-disk cache in those circumstances because the head doesn't have to search all over the disk? Regards, Erik Smit P.S.: Pardon me if I sound newbieish, I'm new to all this. :)
