1 Feb 2008 02:28
RE: Channel bonding problems with 1950s and 2748 switch
<Thomas_Chenault <at> dell.com>
2008-02-01 01:28:15 GMT
2008-02-01 01:28:15 GMT
> It's my understanding that bonding modes 0, 1, and 2 require link aggregation on the switch Modes 0 (balance-rr) and 2 (balance-xor) require link aggregation on the switch. Link aggregation should not be configured on the switch for mode 1 (active-backup), mode 5 (balance-tlb), or mode 6 (balance-alb). > I never seem to get more than the throughput a single card would provide This is normally attributable to the testing procedure used and the way most of the bonding modes work. In balance-xor (with the traditional hashing policy), balance-alb, and balance-tlb, a single slave interface is selected to communicate with any given host. This means that the data rate through the bond to any single host will never exceed the capacity of a single interface. If testing is conducted such that the bond is used to communicate with multiple hosts simultaneously, it can be shown that the total throughput of the bond exceeds the capacity of a single slave. The balance-rr mode can exceed the capacity of a single interface in communication with a single host. In many applications this potential is never truly realized. The problem is that TCP expects segments to arrive in order and this rarely happens when they are being transmitted from multiple interfaces. The outbound data rate of the bond may be higher, but often this is due to retransmissions rather than useful communications. In recent versions of bonding, 2.6.3 and later, a xmit_hash_policy(Continue reading)
Matthias
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