After thinking about it overnight, I realized I think in terms of 1 drive is 1 filesystem. That is a fatal trap for defragment. > When I only worried about a few OEM drives, I used to read the zone > geometry from the drive to see where each speed transition was as the > density decreased. But that is just not worth the effort in linux > filesystems IMO, it is enough to pack low. So I retract that we don't care about zone geometry, we need to care deeply, but not in the sense of how moving short distances on a drive affects the performance. What we need to ensure is that the placer algorithm does not span across partitions as in: ["/" 100GB created] [300GB other] [100G LVM added to "/"] so the filesystem thinks it is 200GB contiguous and the defragmenter thinks address 90GB is closer to address 110 GB than 90GB is to 50GB. jim -- 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
