IPMI Network in 3.x

Question

Are the Management and IPMI IP's/Gateway required to be the same network on a 3.x install? I have heard they need to be on the same network, but have read differently in the 3.x pre-site guide that only talks about them being routable to the XMS machine (which they will be).

Can someone confirm the requirements for a 3.x install please? I have been lucky enough in the past with them all on the same network so this is the first time hitting the requirement for different networks that would be routable through different mgmt. and IPMI gateways.

Thanks.

Kumar_A · Accepted Answer

Correct, we have not tested with the IP addresses being on different subnets and the recommendation is to have all the storage controller, management and IPMI addresses on the same subnet (XMS can be on a different network, but should be routable to the other IP addresses). However, if you need to have these IP addresses on separate subnets, I would recommend submitting an RPQ to enable us to evaluate the scenario and provide our recommendation.

To answer your question about the VLANs on eth0 – we recommend that the management and IPMI IP addresses be in the same network, but an RPQ should be submitted otherwise. Needless to say, I will get this clarified in our product documentation.

Just to clarify on a comment you made earlier – IPMI is not going away with 4.0 release. The only change that we did in 4.0 was to enforce the implementation of management and IPMI addresses to be on different ports on the storage controller. With pre-4.0 releases, you had the option of having both the management and IPMI communication happening on the same port or different ports.

Hope this helps.

echolaughmk · Answer

I'm not sure how much this ECN site is being moderated, so I will post back to my questions as I receive answers for others to utilize in their travels.

I was told through a support case that ALL IP's needed to be on the same network, yet there is no supporting documentation for this that I can find so I have asked for it from support. The only document that discusses the IP requirements is the pre-site that I can find and that only calls out that the IPMI addresses need to be able to communicate with the XMS (which it would in my case).

Once I have the document or the snippet of calling this out, I will provide it here since I know some of these restrictions are not documented in the current documentation set unfortunately.

echolaughmk · Answer

I'm not sure how much this ECN site is being moderated by EMC Engineering like the other product sites are moderated by engineering, so I will post back to my questions as I receive answers for others to utilize in their travels since this one has gone unanswered.

This question seems to be a tough one given the lack of documentation out there on this topic so after working it through support, it seems like you can have different IP addresses for the SC's and IPMI assuming they are all on the same LAN and accessible by the XMS. What is still unknown and suggested against is to have different VLANS on the same ETH0 port on the storage controllers. Given I haven't gotten a definitive answer yet, I will end up redoing the bank of IP's with my customer due to this limitation.

My suggestion for product management would be to clarify this in the docs if these limitations are different than above. I realize the IPMI requirements go away in 4.x, but as a cluster is expanded it is very likely that the new IP's for the storage controllers could be on a different network (still routable to the XMS). If having 2 vlans on the same ETH0 port with different gateways is, indeed, a limitation, it would be nice to have confirmation.

-Keith

Kumar_A · Answer

The recommendation is to have all IPs for the storage controllers in the same subnet – the idea being that different subnets might have different firewalls and we want to avoid that potential problem.

Thanks for pointing out that it is not clearly documented anywhere – I am working with the documentation team to bring this to their notice. Thank you for pointing this out.

echolaughmk · Answer

Thanks Avi,

I concur on it being the recommended approach as well. However, I just needed the clarification that is wasn't "unsupported" in a configuration where they are on different subnets as long as the XMS can reach them all - which is sounds like you are saying is OK, although not recommended.

In my case it's not so much about firewalls as expansion when customer go to add a brick down the line and might not be able to keep the future IP's on the same subnet.

One thing that I still have support researching and I'm not sure if you might know through your channels is if ETH0 can support 2 subnets (only for 3.x) on the same NIC - so the MGMT IP would be subnetA with gatewayA and its IPMI IP would be subnetB with gatewayB - do you know if that is supported?

Thanks for running with the documentation update...definitely helps us out here in the field!

echolaughmk · Answer

Thanks Avi...that answer is great...I would suggest that is the type of information that make it into the release notes or site prep guide as I can see others asking it for expansion scenario's.

Thanks for the clarification on the IPMI.

XtremIO

IPMI Network in 3.x

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