AFAIK Open-E uses the default CFQ I/O scheduler and I was wondering if there is some way to change that to deadline (per array or system-wide). DRBD seems to benefit greatly from this with high speed write back enabled RAID controllers (see http://www.drbd.org/users-guide/s-latency-tuning.html for more info). It would also be nice if could be tuned further by setting different iosched values.