In a general sense there is no pre-check prior to adding node to a cluster, however I personally think it is a good idea to have a burn period of new hardware. What I mean is, turn the nodes on do not plug in any IB cables, and create a cluster of 1 to sit and spin its disks for a day or two. This would help to catch any possible hardware failures that may occur due to any possibly rough handling during shipping and what not.

Just a suggestion. Many customers simply add nodes when they get them, but I think a burn period is good so that the risk of service interruption due to any possible early hardware failures is reduced. You can then reformat the nodes and add them to the existing clusters once this is done.

If you are adding 2x X210 to existing X210 cluster just make sure Internal IP address has at least two free IPs for each subnet.

If you are adding 2x X210 to existing X200 isilon cluster, be sure that the cluster must be updated to OneFSv7.2.1 or higher.

X210 only supports OneFSv7.2.1 or later.

Also, in that case after adding X210 to the cluster, you need to make node class compatibility and ssd compatibility settings active.