Tag: bonding

Configure Bond (802.3ad LACP) device in CentOS 8 – configuration files

Upgrading to a bond device is a common step when the server exhausts its current network port bandwidth.
The hardware setup of the bond example here is:

  • two 10G network cards – ens1f0 and ens1f0
  • bond name – bond0
  • bond mode – 802.3ad – Link Aggregation Control Protocol (LACP)

The systemd reconfiguration procedure consists of:

  • Stop the network target 
    systemctl stop network
  • Set several configuration files – network device files for the network interfaces, bonding interface – master and slave devices.
  • Start the network target 
    systemctl start network

*Note: the 802.3ad bonding mode needs aditional configuration in the switch of which the server is connected.

The example here is using CentOS 8 configuration file to make a permanent (i.e. persistent over reboots using the CentOS 8 network configuration files) bonding configuration.
Check out the official bonding documentation for all modes and options – https://www.kernel.org/doc/Documentation/networking/bonding.txt.

CONF 1) Configure the network interfaces.

The interface should be in down state in the configuration file.
Interface 1 – /etc/sysconfig/network-scripts/ifcfg-ens1f0:

TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=dhcp
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME=ens1f0
UUID=3b399a23-570e-45ed-9369-4ff5b87efb2c
DEVICE=ens1f0
ONBOOT=no

Interface 2 – /etc/sysconfig/network-scripts/ifcfg-ens1f1:

TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=dhcp
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME=ens1f1
UUID=ecdc5d5b-9739-4424-9d67-362411974281
DEVICE=ens1f1
ONBOOT=no

CONF 2) Configure bonding master device – create a bonding group bond0

This device should be started up at boot.
Bonding device 1 – with name bond0 – /etc/sysconfig/network-scripts/ifcfg-Bond_connection_1:

BONDING_OPTS="downdelay=200 miimon=100 mode=802.3ad updelay=200"
TYPE=Bond
BONDING_MASTER=yes
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=none
IPADDR=10.10.10.10
PREFIX=24
GATEWAY=10.10.10.1
DNS1=10.10.10.2
DNS2=10.10.10.3
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_PRIVACY=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME="Bond connection 1"
UUID=f0a35f9a-20e4-484e-850c-689128642555
DEVICE=bond0
ONBOOT=yes

BONDING_OPTS are specific options for the bonding group with name bond0 and the bonding mode is set here, too.

CONF 3) Configure bonding slave devices – the two network cards

Adding the two network cards to the bonding group bond0. These devices should be started up at boot.
Interface 1 – /etc/sysconfig/network-scripts/ifcfg-bond0_slave_1:

HWADDR=90:E2:BA:8A:13:8C
TYPE=Ethernet
NAME="bond0 slave 1"
UUID=c49e0ced-6411-41fa-9a3b-a01a430664a7
DEVICE=ens1f0
ONBOOT=yes
MASTER=bond0
SLAVE=yes

Interface 2 – /etc/sysconfig/network-scripts/ifcfg-bond0_slave_2:

HWADDR=90:E2:BA:8A:13:8D
TYPE=Ethernet
NAME="bond0 slave 2"
UUID=90de1cad-1d9f-48cb-8e5a-7d8bfdde91d2
DEVICE=ens1f1
ONBOOT=yes
MASTER=bond0
SLAVE=yes

Set up (802.3ad LACP) bonding when installing CentOS 8

This article is to show how the user could install CentOS 8 (the steps are the same with CentOS 7) with a much complex network setup such as Bonding device in 802.3ad mode (LACP – Link Aggregation Control Protocol).
The whole installation procedure is not included here, but there are couple of other article on the subject “Install CentOS 7 or CentOS 8”:

Similar configuration files will be generated as in Configure Bond (802.3ad LACP) device in CentOS 8 – configuration files

SCREENSHOT 1) Click on “Network and Host Name” to configure the machine networking.

main menu
Installation Summary – Network and Host Name

Keep on reading!

Pages: Page 1, Page 2, Page 3

bonding – write error – device or resource busy – operation not permitted

Recently, there was a little bit of confusion when following the article about activating network bonding without ifenslave – How to enable Linux bonding without ifenslave. At first, there were couple of errors:

livecd ~ # echo balance-alb > /sys/class/net/bond0/bonding/mode
-bash: echo: write error: Device or resource busy
livecd ~ # echo "+enp129s0f0" > /sys/class/net/bond0/bonding/slaves
-bash: echo: write error: Operation not permitted

Or similar error when changing the bonding mode:

livecd ~ # echo 4 > /sys/class/net/bond0/bonding/mode
-bash: echo: write error: Directory not empty
livecd ~ # echo 802.3ad > /sys/class/net/bond0/bonding/mode
-bash: echo: write error: Directory not empty

The server just booted in rescue live cd and there is no active network configuration:

SCREENSHOT 1) Apparently, the /sys/class/net/bond0/bonding/mode and /sys/class/net/bond0/bonding/slaves are in read only state.

No writes means no new configuration could be installed and the bonding cannot be configured (reconfigured).

main menu
device or resource busy – operation not permitted

Bonding mode could be changed only when the bonding device is in DOWN state.

Network interfaces could be added to the boding device only if they were in DOWN state, too.

In addition, changing bonding mode could only happen if there were no network interfaces added to the bonding interface.

Keep on reading!

How to enable linux bonding without ifenslave

ifenslave is no more needed when configuring bonding under Linux. There are situations when we could have no network link without bonding, because of specific switch configuration and we do not have ifenslave package installed. We can configure bonding manually via Sysfs.
Here are the steps to configure bond0 in adaptive load balancing with two network cards in slave mode:

modprobe bonding
echo balance-alb > /sys/class/net/bond0/bonding/mode
echo +eth0 > /sys/class/net/bond0/bonding/slaves
echo +eth1 > /sys/class/net/bond0/bonding/slaves
ifconfig bond0 192.168.1.1 netmask 255.255.255.0 up

The adaptive load balancing does not require any special network setup. On the contrary, the mode “802.3ad” could be used only if you enable bonding of the interfaces of your server to have a network link.

echo 802.3ad > /sys/class/net/bond0/bonding/mode

For more detailed explanation:

https://www.kernel.org/doc/Documentation/networking/bonding.txt

If the “/sys/class/net/bond0” is missing you should do:

echo +bond0 > /sys/class/net/bonding_masters