DISCLAIMER : Please note that blog owner takes no responsibility of any kind for any type of data loss or damage by trying any of the command/method mentioned in this blog. You may use the commands/method/scripts on your own responsibility.If you find something useful, a comment would be appreciated to let other viewers also know that the solution/method work(ed) for you.

Ethernet Bonding in linux

NICteaming/bonding is used mostly in scenarios where you cannot afford to loose connectivity due to ethernet failover issues and also it has many other advantages like to distribute bandwidth, fault tolerance etc

Let us begin with the configuration:

Make sure you have two(at least) physical Ethernet cards in your Linux machine.
Edit the configuration files of both the Ethernet cards with the options as shown below

# less /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
MASTER=bond0
USERCTL=no
SLAVE=yes
BOOTPROTO=none
TYPE=Ethernet
ONBOOT=yes
# less /etc/sysconfig/network-scripts/ifcfg-eth1
DEVICE=eth1
TYPE=Ethernet
ONBOOT=yes
BOOTPROTO=none
MASTER=bond0
SLAVE=yes
USERCTL=no
Create a new file inside /etc/sysconfig/network-scripts/ifcfg-bond0 with the parameters as shown below# less /etc/sysconfig/network-scripts/ifcfg-bond0
DEVICE=bond0
IPADDR=192.168.0.100
GATEWAY=192.168.0.1
NETMASK=255.255.255.0
USERCTL=no
BOOTPROTO=none
ONBOOT=yes
PEERDNS=yes

In RED HAT 5
Append/make these following changes in below mentioned file as shown

# vi /etc/modprobe.conf
alias bond0 bonding
options bond0 mode=1 miimon=100

 In RED HAT 6
You will not find modprobe.conf file so you need to define bonding option inside your ifcfg-bond0configuration file as shown below

# less /etc/sysconfig/network-scripts/ifcfg-bond0
DEVICE=bond0
IPADDR=192.168.0.100
GATEWAY=192.168.0.1
NETMASK=255.255.255.0
DNS1=8.8.8.8
BONDING_OPTS="miimon=100 mode=1"
USERCTL=no
PEERDNS=yes
BOOTPROTO=none
ONBOOT=yes

Here, you can use different values for mode and miimon

Different types of modes available for NIC bonding:

You can configure NIC Teaming for various purposes. So while configuration you will have to specify the purpose for which you want to utilize NIC Teaming.

Here are the list of available options

balance-rr or 0 : Sets a round-robin policy for fault tolerance and load balancing. Transmissions are received and sent out sequentially on each bonded slave interface beginning with the first one available.

active-backup or 1: Sets an active-backup policy for fault tolerance. Transmissions are received and sent out via the first available bonded slave interface. Another bonded slave interface is only used if the active bonded slave interface fails.

balance-xor or 2: Sets an XOR(exclusive-or) policy for fault tolerance and load balancing. Using this method the interface matches up the incoming request's MAC Address with the MAC Address for one of the slave NICs. Once the link is established, transmissions are sent out sequentially beginning with the first available interface.

broadcast or 3: Sets a broadcast policy for fault tolerance. All transmissions are sent on all slave interfaces.

802.3ad or 4: Sets an IEEE802.3ad dynamic link aggregation policy. Creates aggregation groups that share the same speed and duplex settings. Transmits and receives on all slave in the active aggregator. Requires a switch that is 802.3ad compliant

balance-tlb or 5: Sets a Transmit Load Balancing (TLB) policy for fault tolerance and load balancing. The outgoing traffic is distributed according to the current load on each slave interface. Incoming traffic is received by the current slave. If the receiving slave fails, another slave takes over the MAC address of the failed slave.

balance-alb or 6: Sets and Active Load balancing (ALB) policy for fault tolerance and load balancing. Includes transmit and receive and load balancing for IPV4 traffic. Receive load balancing is achieved thorugh ARP negotiation

What is miimon in NICTeaming?

Specifies (in milliseconds) how often MII link monitoring occurs. This is useful if high availability is required because MII is used to verify that the NIC is active. To verify that the driver for a particular NIC supports the MII tool, type the following command as root:

# ethtool <interface_name> | grep "Link detected:"

# ethtool eth0 | grep "Link detected:"
        Link detected: yes

# ethtool eth1 | grep "Link detected:"
        Link detected: yes


So for our demo purpose we will use mode 1 make NIC bonding for Fault Tolerance

Now time to load the bonding module

# modprobe bonding

Restart the network interface to make the changes affect

# service network restart

Verify if your configuration has worked properly using below command

# cat /proc/net/bonding/bond0
Ethernet Channel Bonding Driver: v3.4.0-1 (October 7, 2008)

Bonding Mode: fault-tolerance (active-backup)
Primary Slave: None
Currently Active Slave: eth0
MII Status: up
MII Polling Interval (ms): 100
Up Delay (ms): 0
Down Delay (ms): 0

Slave Interface: eth0
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: 5f:5g:56:3v:23:54

Slave Interface: eth1
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: 4f:76:23:v4:76:f6

Check your network status

# ifconfig
bond0     Link encap:Ethernet  HWaddr R5:4G:45:6H:14:54
          inet addr:192.168.0.100  Bcast:192.168.0.1  Mask:255.255.255.0
          UP BROADCAST RUNNING MASTER MULTICAST  MTU:1500  Metric:1
          RX packets:675166546 errors:0 dropped:0 overruns:0 frame:0
          TX packets:60123345 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:717558660669 (668.2 GiB)  TX bytes:680121390699 (633.4 GiB)

eth0      Link encap:Ethernet  HWaddr 5F:5G:56:3V:23:54
          UP BROADCAST RUNNING SLAVE MULTICAST  MTU:1500  Metric:1
          RX packets:675130834 errors:0 dropped:0 overruns:0 frame:0
          TX packets:601230970 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:717553120481 (668.2 GiB)  TX bytes:680121390699 (633.4 GiB)
          Interrupt:169 Memory:96000000-96012800

eth1      Link encap:Ethernet  HWaddr 4F:76:23:V4:76:F6
          UP BROADCAST RUNNING SLAVE MULTICAST  MTU:1500  Metric:1
          RX packets:35302 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:5540188 (5.2 MiB)  TX bytes:0 (0.0 b)
          Interrupt:122 Memory:94000000-94012800



This post should help you with ethernet bonding in linux


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PowerPath Powermt Commands - EMC

Below are  the 10 major commands to check the POWER PATH config on unix servers.
Please follow the below commands

1.powermt display ====>Display High Level HBA I/O Paths
2.powermt display dev=emcpowera ===>Display for specific LUN
3.powermt display dev=all ====> Display All Attached LUNs
4.powermt check_registration ===> Display PowerPath Registration Key / Status
5.powermt display options ===> Display EMC PowerPath Options
6.powermt display hba_mode ====> Display PowerPath HBA Mode
7.powermt display paths – Display available I/O Paths.
8.powermt displays port_mode ===>Display Port Status
9.powermt version ====> Display EMC PowerPath Version
10.powermt check ===>Check the I/O Paths


1. #powermt display ===>Display High Level HBA I/O Paths

Example output:

Symmetrix logical device count=212
CLARiiON logical device count=0
Hitachi logical device count=0
Invista logical device count=0
HP xp logical device count=0
Ess logical device count=0
HP HSx logical device count=0
==============================================================================
----- Host Bus Adapters ---------  ------ I/O Paths -----  ------ Stats ------
###  HW Path                       Summary   Total   Dead  IO/Sec Q-IOs Errors
==============================================================================
   3 0/4/0/0/0/1                   optimal     424      0       -     0    848
   5 0/5/0/0/0/1                   optimal     424      0       -     0    848

2. #powermt display dev=emcpowera ===>Display specific LUN

When there are multiple LUNs connected to a server, you might want to view information about a specific LUN by providing the logical name of the LUN as shown below.

3.#powermt display dev=all ====> Display All Attached LUNs

Mostly we used to run this command powermt, which will display all the attached logical devices to the server.

Pseudo name=disk915
Symmetrix ID=000290103691
Logical device ID=06B8
state=alive; policy=SymmOpt; priority=0; queued-IOs=0;
==============================================================================
--------------- Host ---------------   - Stor -   -- I/O Path --  -- Stats ---
###  HW Path               I/O Paths    Interf.   Mode    State   Q-IOs Errors
==============================================================================
   3 0/4/0/0/0/1.0x5006048c52a862e7.0x40a6000000000000 c14t4d6   FA  8cB   active  alive       0      2
   3 0/4/0/0/0/1.0x5006048c52a862f7.0x40a6000000000000 c15t4d6   FA  8dB   active  alive       0      2
   5 0/5/0/0/0/1.0x5006048c52a862e8.0x40a6000000000000 c16t4d6   FA  9cB   active  alive       0      2
   5 0/5/0/0/0/1.0x5006048c52a862f8.0x40a6000000000000 c17t4d6   FA  9dB   active  alive       0      2

Pseudo name=disk988
Symmetrix ID=000290103691
Logical device ID=074B
state=alive; policy=SymmOpt; priority=0; queued-IOs=0;
==============================================================================
--------------- Host ---------------   - Stor -   -- I/O Path --  -- Stats ---
###  HW Path               I/O Paths    Interf.   Mode    State   Q-IOs Errors
==============================================================================
   5 0/5/0/0/0/1.0x5006048c52a862e8.0x40dc000000000000 c16t11d4  FA  9cB   active  alive       0      2
   3 0/4/0/0/0/1.0x5006048c52a862e7.0x40dc000000000000 c14t11d4  FA  8cB   active  alive       0      2
   3 0/4/0/0/0/1.0x5006048c52a862f7.0x40ce000000000000 c15t9d6   FA  8dB   active  alive       0      2
   5 0/5/0/0/0/1.0x5006048c52a862f8.0x40ce000000000000 c17t9d6   FA  9dB   active  alive       0      2

Details:

a. Pseudo name=emcpowera – The device name that can be used by the server. For example,
/dev/emcpowera.
b. CLARiiON ID=AAA00000000000 [dev-server] - EMC CLARiiON CX3 serial number and
the server name.
c. Logical device ID=11111111 [LUN 1] – LUN number. For example, LUN 1.
d. state=alive; policy=CLAROpt; – This displays that this particular LUN is valid and using
the CLAROpt policy.
e. Owner: default=SP B, current=SP B – This indicates that the default (and current) owner for
this LUN is storage processor SP B.


4. powermt check_registration – Display PowerPath Registration Key / Status


If you’ve lost the PowerPath registration key that you’ve used during the EMC PowerPath installation, you can retrieve it using the following command.

# powermt check_registration
Key AAAA-BBBB-CCCC-DDDD-EEEE-FFFF
  Product: PowerPath
  Capabilities: All


5. #powermt display options ===> Display EMC PowerPath Options


Displays the high level EMC SAN array options.


6.#powermt display hba_mode ====> Display PowerPath HBA Mode


This is similar to #1, but displays whether hba is enabled or not, as shown in the last column of the output.

Examble output:

Symmetrix logical device count=212
CLARiiON logical device count=0
Hitachi logical device count=0
Invista logical device count=0
HP xp logical device count=0
Ess logical device count=0
HP HSx logical device count=0
==============================================================================
----- Host Bus Adapters ---------  ------ I/O Paths -----  Stats
###  HW Path                       Summary   Total   Dead  Q-IOs Mode
==============================================================================
   3 0/4/0/0/0/1                   optimal     424      0     0 Enabled
   5 0/5/0/0/0/1                   optimal     424      0     0 Enabled

7.powermt display paths ===> Display available I/O Paths.


This displays all available path for your SAN device.

8.powermt displays port_mode ===>Display Port Status


Displays the status of the individual ports on the HBA. i.e Whether the port is enabled or not.

9.powermt version ====> Display EMC PowerPath Version


How to identify the version number of EMC PowerPath software?

10.powermt check ===>Check the I/O Paths


If we made changes to the HBA’s, or I/O paths, then run the powermt check, to take appropriate action. For example,
if you manually removed an I/O path, check command will detect a dead path and remove it from the EMC path list.

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