Installation guide

Some drivers may require driver parameters in the /etc/modprobe.conf file. For example, the driver

e1000 may be used with flow control parameter specified as

option e1000 FlowControl=1,1

It is recommended to configure network switches and NICs for autonegotiation and let them agree on the right

combination of flow control settings.

Network Interface Bonding

Conceptually the NIC bonding is a method for aggregating multiple network interfaces into a single logical

bonded interface. The behavior of the bonded interfaces depends upon the mode; generally speaking, modes

provide either hot standby or load balancing services.

The most popular is the active-backup mode. This mode provides fault tolerance. Only one slave interface in the

bond is active. A different slave becomes active if, and only if, the active slave fails. The bond's MAC address

is externally visible on only one port (network adapter) to avoid confusing the switch.

If active-backup mode is used on Oracle 10g RAC interconnect and the interconnect is implemented with the

separate switches, it may be desirable to configure primary interfaces on all cluster nodes to be connected to the

same switch. In this case, the interconnect traffic is localized on the same switch and avoids interswitch link.

The adaptive load balancing mode (balance-alb) provides transmit and receive load balancing and does not re-

quire any special switch support.

There are a couple of issues to consider. The first is that by default, when bringing up a server with bond de-

vices in the configuration, the NIC drivers will not have been loaded yet when the bonding driver initializes.

Therefore it is entirely possible that the bonding driver's attempts to start the interfaces belonging to that bond

will result in those NIC's receiving different device names from the kernel. So the best way to start bonding is

to force the system to load the NIC drivers first, in the same order your /etc/modprobe.conf shows. For

example, if your eth0 and eth1 devices use bnx2, and eth2 and eth3 use e1000 drivers, then you want to mod-

probe bnx2 first, then e1000. After that you can load the bonding driver and it should find the NICs it is look-

ing for where it expects to find it (with the correct device name). The order in which NIC drivers are loaded de-

termines the ethX device names the kernel will assign .

The second issue is the syntax necessary to load the bonding driver multiple times. In order to use different

bonding options on different bond devices, you have to load the bonding driver multiple times. Specifying

"max_bonds=X" (where X is > 1) will not provide multiple bond devices capable of having different options.

The following two lines are 'install' lines from the /etc/modprobe.conf. Note that there should not be any

'alias bond0 bonding' lines for any bond interface as this will confuse the bonding driver and/or system init-

scripts. These two lines are the only bonding related lines that should be present in /etc/modprobe.conf:

install bond0 /sbin/modprobe bnx2; /sbin/modprobe e1000; \

/sbin/modprobe -i bonding -o bond0 mode=balance-alb \

arp_ip_target=192.168.0.19 arp_interval=200

install bond1 /sbin/modprobe bnx2; /sbin/modprobe e1000; \

/sbin/modprobe -i bonding -o bond1 mode=1 \