DRBD, NIC bonding, load balancing, Openfiler...
We have 2 Openfiler SANs utilizing DRBD for HA/mirroring. DRBD data flows between the 2 servers at 1gb/s via a directly connected x-over cable.
This poses the problem of that 1gb/s link being a bottleneck as harddisk I/O could potentially be double what the 1gb/s link can handle.
So... you just set up a bonded interface, right? Well no it doesnt seem to be as simple as that. From what i can gather the only bonding mode which can put a single stream of data onto serveral NICs is balance-rr (round robin), but due to its overheads its going to take 3 or 4 NICs bonded together to reach the 2gb/s target.
I have set up balance-rr by editting th modprobe.conf file, is this the only file that needs editting? Under testing its almost asthough the bond believes it can only transmit at 1gb/s total instead of 1gb/s per NIC.
Is there any other files which need editting? (documentation on balance-rr is very limited so any help much appreciated).
Has anyone done something similar? How did you do it?