Shared Ethernet Adapter configuration with two networks
When we talk about production environment, every administrator should consider all possible single point of failures (SPOFs) and resilience in architecture. Here, we are talking about network to the VIOS and LPARs and this architecture removes maximum possibilities of SPOF in terms of network and provides a separate network that can communicate with back up server, access application, and databases swiftly.
This kind of architecture is widely used, where users are accessing the server 24x7, and administrator wants to back up data without impacting the user's bandwidth.
Figure 1. Architecture diagram
In this architecture, we have two VIOS instances, with two separate Host Ethernet Adapters to each VIOS, and it will be dedicated to the respective VIOS in the promiscuous mode. Each HEA incorporates one Shared Ethernet Adapter.
Two Ethernet adapters of each VIOS are connected to different networks (public and private) and every LPAR will be having a minimum of two virtual Ethernets with different virtual LAN (VLAN) IDs.
For better understanding, we divide the configuration in to two steps.
Step 1: Create a VIOS partition / VIOS partition configuration
On VIOS, we need to create four virtual Ethernet ports. You can make sure that physical HEA is in the promiscuous mode.
- In the HMC window, check the frame and select the VIOS instance A.
- Go to configuration and click Manage Profile.
- In the Manage Profile window, there is an option for virtual I/O, from where you can create virtual adapters, Ethernet, fiber and Small Computer System Interface (SCSI) adapters. You need to select Ethernet.
- Perform the same steps on the VIOS instance B.
After all the Ethernets are created, you can see four Ethernets on every VIOS instance.
Figure 2: Ethernet adapters
Set up all four virtual Ethernets with the following configuration.
Figure 3: Ethernet adapter-1 Port Virtual Ethernet (VLAN ID 1) Priority 1
Figure 4: Ethernet adapter-2 Port Virtual Ethernet (VLAN ID 99)
Figure 5: Ethernet adapter-3 Port Virtual Ethernet (VLAN ID 2) Priority 1
Figure 6: Ethernet adapter-4 Port Virtual Ethernet (VLAN ID 88) Priority 1
The above shown configuration is for VIOS-A. You need to apply the same configuration for VIOS-B, with the small change.
1st Virtual Ethernet Adapter: Port Virtual Ethernet (VLAN ID 1) Priority 2
2nd Virtual Ethernet Adapter: Port Virtual Ethernet (VLAN ID 99)
3rd Virtual Ethernet Adapter: Port Virtual Ethernet (VLAN ID 2) Priority 2
4th Virtual Ethernet Adapter: Port Virtual Ethernet (VLAN ID 88)
With this configuration, you will be able to see the six Ethernet adapters on VIOS-A and VIOS-B (two physical adapters and four virtual ports).
Figure 7: All Ethernet adapters on console
Step 2: Create a Shared Ethernet Adapter
Here, we need to create a Shared Ethernet Adapter that includes one physical Ethernet port and two virtual ports. With the help of the following command, we can create two different Shared Ethernet Adapters.
$mkvdev -sea ent0 -vadapter ent2 -default ent2 -defaultid 1 -attr ha_mode=auto ctl_chan=ent3 $mkvdev -sea ent1 -vadapter ent4 -default ent4 -defaultid 2 -attr ha_mode=auto ctl_chan=ent5
Figure 8: Shared Ethernet Adapters
We need to perform the same action on VIOS-B.
mkvdev -sea ent0 -vadapter ent2 -default ent2 -defaultid 1 -attr ha_mode=auto ctl_chan=ent3 $mkvdev -sea ent1 -vadapter ent4 -default ent4 -defaultid 2 -attr ha_mode=auto ctl_chan=ent5
Here, both Shared Ethernet Adapters will be able to communicate with different networks at the same time and both VIOS are redundant to each other.
To check the primary Ethernet adapter from both VIOS, we can use the following command.
entstat -all en6 |grep State entstat -all en7 |grep State
On the primay VIOS, verify whether the Ethernet state is PRIMARY.
Figure 9: en6 PRIMARY
On the secondary VIOS, verify whether the Ethernet state is BACKUP.
Figure 10: en7 BACKUP
As we know, by default, VIOS-A is primary for the Network and Fiber Optic (DISK, Storage) communication. To avoid this load and make efficient use of both VIOS, we can prioritize VIOS-B as a primary for network traffic and VIOS-A for Primary for Fiber Optic Communication. To do this, we need to swap priorities of VIOS-B from 2 to 1 and for VIOS-A, we need to swap priorities from 1 to 2.