Comment 8 for bug 129488

n.b. readahead is only half of the problem.

my 4 disk RAID10 array is 2/3 of the speed of my disk disk RAID0 array for big sequential reads. this is complete madness, as there are twice as many disks to read from in the RAID10 case. ANyway, not strictly related to this bug, but the interaction of raid, lvm and overlying fs has clearly never been thought through for desktop users (who often have lots of disks nowadays).

my eyes were watering after 15 mins looking at the lvm, mdadm and ext3 man pages. stride, chunks, superblock offsets, mayhem.