NIC Bonding

carlosinfl · 07-26-2011, 01:03 PM

I created a NIC bond0 on RHEL 5.6 about a year ago and I noticed today that the bond works but it's doing fail over (round-robin) rather than bonding them together to get more throughput performance via my two NIC's.

I found this article:

https://access.redhat.com/kb/docs/DOC-34633

My question assuming my switch supports it, what 'mode' will allow my two NIC's to operate as one and allow more throughput rather than fail over?

Code:

[root@iback ~]# cat /proc/net/bonding/bond0 
Ethernet Channel Bonding Driver: v3.4.0-1 (October 7, 2008)

Bonding Mode: load balancing (round-robin)
MII Status: up
MII Polling Interval (ms): 0
Up Delay (ms): 0
Down Delay (ms): 0

Slave Interface: eth0
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0

Slave Interface: eth1
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0

acid_kewpie · 07-26-2011, 02:54 PM

well it depends what throughput you mean. tx or rx? Well in fact the only switch support required is for recieve throughput, which is mode 4, 802.3ad, etherchannel on a Cisco switch. Note that this uses MAC or IP logic to determine the connection to use, so if it's 1 device to another, you'll still only use one connection.

but RR IS Load balancing. Why would that possibly be failover??

carlosinfl · 07-28-2011, 07:44 AM

Quote:

Originally Posted by acid_kewpie

but RR IS Load balancing. Why would that possibly be failover??

I was under the assumption that load balancing is like RAID 1 for NIC's. If one NIC fails, the other is there to pick up the slack and no downtime for the server...no?

acid_kewpie · 07-28-2011, 08:04 AM

even at a basic language level that surely doesn't sound right to you? they are "balanced". a round robin means to go round in a loop whever you apply the term.

SL00b · 07-28-2011, 08:25 AM

In ifcfg-bondn there's a line for options, like this: BONDING_MODULE_OPTS='mode=active-backup miimon=100'

It's the mode setting that controls the behavior. Mine here is set up like yours, with only one member of the bond is actively arping on the bond IP at any time.

There are other mode options for accomplishing load balancing. Take a look at the options here: http://www.linuxhorizon.ro/bonding.html