> I have no idea wether [several journal flushes per second] is high or low. It should be killing you. So the main question is who is issuing these small sync writes. As already mentioned, per filesync write you get a WAPBL journal flush which ends up in two disc flushes (one before and one after).
> This is a two-disk RAID 1 Wait, this is a Level 1 RAID? The you don't have RMW. You may compare write througput to read throughput.
