Question about how Linux bonding mode=2 handles changing loads from a single client doing video editing over a network. Here's the specific scenario. I have 4 Gigabit Ethernet lines running from a Linux server to a switch that supports static link aggregation. I have configured the Linux adapters with: modprobe bonding mode=2 ifenslave bond0 eth0 eth1 eth2 eth3 If I connect 4 Windows clients to the switch, I can see that as each client "comes on line" and starts requesting data, the data is being transmitted from a different port out of the 4 ports that are part of the "static aggregation" or trunk. So, the load is getting balanced between the four Gigabit channels. So far so good. And I see great performance on the editing workstations. However, my question is, what happens if the load changes? For instance, say today I am editing "compressed DV video" (3.8 MB/sec) on eight clients. If the balancing is fair, I might end up with two clients sending and receiving data on each Gigabit port that's part of the aggregation or trunk. But tomorrow let's say I start editing "uncompressed standard definition video" (roughly 22 MB/sec) on two clients. And let's say it just so happens that yesterday those two clients were both "assigned" the same port for communicating with the server. Communicating through the same port would have been fine for compressed DV video, but might not be so good for two streams of 22 MB/sec uncompressed video. Will the switch and/or the Linux bonding mode=2 algorithm reassign which port is associated with which client based on the changing load? Or am I stuck with the original port assignment until I reboot the client or the switch? And what happens if I'm editing DV video (3.8 MB/sec) at 9 am, but change to uncompressed video (22 MB/sec) at 10 am? The balance between clients that worked at 9 am might be terrible at 10 am. I haven't actually seen this problem in the real world, but I'm wondering how the "static link aggregation" and "balanced XOR" standard handles this. In contrast, I can see that when I set the bonding module to "mode=0", the data is ALWAYS parceled out between the four ports. But I get terrible performance on the client workstations when editing uncompressed video. There must be a lot of "out of order packets" with "mode=0" that trip up the workstation running the video editing program. So, "mode=2" seems like a better bet. But I would like to understand how it works over time. Insight would be appreciated. Andy Liebman - : send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
