I've been trying to troubleshoot an issue with this setup without success, hopefully you can help me.
With this current setup (diagram attached), I can perform a NAS failover from storage controller SPA to SPB but then I cannot failback from SPB to SPA. During the failback the datastore mounted on ESXi becomes inaccessible, if I failover the NAS again from SPA to SPB the datastore becomes available again automatically.
Here are the scenarios which worked for me, one test at a time:
1) Turning off switch 1, the datastore on ESXi remains mounted, good, turn it back on.
2) Turning off switch 2, the datastore on ESXi remains mounted, good, turn it back on.
3) Failing over the NAS on storage controller SPA to SPB, the datastore on ESXi remains mounted, good.
Here's the scenario I'm having trouble with:
1) Failing back the NAS on storage controller SPB to SPA after a successful failover from the above scenario
I've also noticed that if I leave the NAS server long enough on the SPB I can eventually failback to SPA without issues, but then it reverses path, I cannot go back to SPA. It seems to only failover once, but never failback unless I give it enough time.
Port-channels and vPC are up successfully without inconsistencies.
The switches are Nexus 3k. Storage is EMC Unity.
Any thoughts on what else I can check/test/do? Much appreciated, thank you!