On Sat, 2005-12-31 at 03:12, Tim wrote:
Unless fragmentation on ext3 file systems is a problem, and I've no evidence to the contrary, then it doesn't matter how the data is put on the drive.
All you have to do is look at the seek time on a disk drive compared to any other computer operation to see what the effect will be if a file that is normally read sequentially is broken into non-contiguous chunks. However aside from the effort the system makes to avoid doing that, the real reason you don't often notice the problem in practice is that frequently-accessed files always live in cache so if you read a file often you only take the speed hit once - and if you don't read it often it probably doesn't matter. Writes also always go through cache and sensible operating systems will sort the write-back into seek order to avoid threshing the head around in the process. So, if you think you have a speed problem caused by your disk, the quick fix is normally to add more RAM.