Update: The developers and the manuals call this Load Sharing but most people think it is called Load Balancing. Perhaps, balancing gives the wrong impression of fine grain packet by packet balancing where we actually have higher level, cruder splitting of the work with Sharing. Below I use the word Balancing but mean Sharing.
I have got a few questions recently on how to set this up as there are announcement with near zero information on setup, the configuration needed and a worked example. So here goes.
For a long time now we have had SEA Failover where the VIOS pair work together to provide a simple to set up at the client VM (LPAR) redundant path to the network. A single virtual Ethernet network is managed between two Virtual I/O Servers (VIOS). The one with the higher priority (lower number) is the primary and does all the network bridging I/O and the secondary does nothing unless the primary is taken down or fails. Then the secondary takes over and does all the network bridging until the primary returned when the primary takes over again.
|SEA Setup image|
mkvdev -sea ent0 -vadapter ent3,ent4,ent5, ent6 -default ent3 -defaultid=10 -attr ha_mode=auto ctl_chan=ent9
Note: I corrected a typo where it had “ctl_chan=42” was wrong, confusing the VLAN id with the network port.
Virtual Ethernet Adapter Properties image
Now let us move on to SEA Failover with Load Balancing
The SEA Failover with Load Balancing pair of VIOS have to vigorously agree which VIOS does what and this is done at the Trunk Adapter level. This is achieved with the Secondary VIOS communicating with the Primary VIOS to volunteer to take over a set of Trunk Adapters (now called Ethernet bridging on the HMC). Once acknowledged they split the network I/O work between them. If later you take a VIOS down or there is a genuine failure the surviving VIOS takes on all the network I/O …. of course.
- Both VIOS must be at Version 18.104.22.168
chdev -dev ent10 -attr ha_mode=sharing
- Load Sharing must be enabled first on the Primary SEA first – the Secondary SEA initiates the load sharing for you want the primary to be ready.
- Obviously, both SEA’s need to be in Load Sharing mode.
- The VLAN id’s of the Trunk adapters must match – If VIOS a has trunk adapter 1 with VLAN id’s say 10 and 20 and a second trunk adapter with VLAN id’s 40 and 50 then the other VIOS needs to have the same combination. This needs careful planned.
- To disable Load Sharing shave the ha_mode to auto. The other options are standby or disabled.Find the current state of the SEA and which is primary but getting to root on the VIOS (oem_setup_env) then
entstat -d ent10 | grep -i state
- The entstat command on the VIOS SEA has other good information like the VLAN id’s.
- If you have a VIOS failure or take a SEA down then once back up, you can restart the Load Sharing with the chdev command above
I hope this helps you get Shared Ethernet Adapter Failover with Load Sharing working.