Weird communication issue on VIO Servers

[KPKIND]

Hi,

I have built 2 vio servers (VIO1 & VIO2)on a P520 with a 2 port eth adapter assigned to each VIO server.Each of the VIO server has 2 sea's (Shared Eth Adapter)with IP on only one one SEA. When my VIO1 comes up it can communicate to the outside network without any issues. But when my VIO2 is coming up, as soon as it reaches c33 during the boot stage the first server stops communicating to the outside network.

I have not yet configured any SEA failover at all. For information the priority on the virtual adapters(Trunk enabled) are 1 on VIO1 and 2 on VIO2. I dont think this will make any diff until I configure SEA failover. Correct me if I am wrong.

What I am surprised is, in the current situation the 2 VIO lpars are completely independent and have got their own dedicated eth adapters and how can LPAR2 influence the behaviour of LPAR1.

Any help is very much appreciated.

Cheers

 

[p5wizard]

Until you define the SEA in failover mode, make sure the 2nd VIOS is unplugged from the network switches.

Also make sure the virtual ethernets defined on both VIOSs have a different TRUNK priority.

If you haven't set any TRUNK priority, perhaps your HMC is downlevel?


HTH,

p5wizard

 

[KPKIND]

Thanks p5wizard for your time.

So do you mean I cannot run two VIO servers without using the SEA failover feature. Or do you mean since I have configured different priorities, I cannot use two VIO servers without using the SEA failover feature.

As mentioned earlier, I have already set different trunk priorities on the virtual ethernets (Priority 1 on VIO1 and 2 on VIO2).

My hmc is at the latest level which V6R1.2

Cheers

 

[KPKIND]

Hi,

I have just tested by changing the trunk priorty of the virtual eth adapter on VIO2 to 1 (same as VIO1) I cannot activate VIO2 anymore. My understanding from this is if you have set different priorities on adapters in the same VLAN on servers VIO1 & VIO2, you should use the SEA FAILOVER feature. If not there should be no adapter that has got "Access external network" enabled in the same VLAN on both the VIO servers.

Hope my understanding is correct. Please correct me if I am wrong.

This arises one more question about earlier versions of VIO where there was no SEA failover feature. I reckon we have configured etherchannel on the AIX client partitions on two virtual adapters connecting to SEA's coming from 2 different VIO servers. So is this facility taken out now as SEA failover is possible at VIO server level.

Cheers

 

[p5wizard]

Gotta think about that some more (also I read OP again, so part of my response was not to the point - sorry :~/)


HTH,

p5wizard

 

[hfaix]

Are you saying you have both VIO servers using the same vlan id...and trunking? I don't think that will work.

 

[KPKIND]

Yes hfaix.. you are right. The cirtual adapters on both the VIO servers are in vlan 40 and both are trunk enabled.

From what I understand after all the troubleshooting is that, in the previous versions before there was a facility for SEA failover, this setup used to work.

I think in the newer versions where SEA failover is introuduced, it doesn't work any more.

Hope that's right.

Cheers

 

[KPKIND]

Sorry Please read the sentence as "From what I understand after all the troubleshooting is that, in the previous versions there was NO facility for SEA failover, this setup used to work.

 

[Gosse]

Just a thought:

Did you put a control channel on the vlan?

 

[p5wizard]

And if so, is that control channel defined for the same VLAN number (different from the SEA VLAN number) for both VIO servers?


HTH,

p5wizard

 

[KPKIND]

Yes it was the problem with control channel only. I have created virtual ethernet adapters in the right VLANS etc but not yet configured the control channel before which I have seen this problem.

I have found the root cause being the rule that there can only be 1 virtual ethernet adapter that can act as a trunk adapter per each VLAN for a frame. So in this case since I had 2 adapters with trunk enabled it did not work. If I had configured control channel on both the vio servers as a part of creation of SEA, then it would have worked fine. The reason being when control channel is configured one acts as a primary and another secondary so at any point of time it is only 1 trunk adapter that is active, which satisfies the basic rule.

Hope this helps.

Cheers