I see your need more clearly now.
You can use the fault suppression feature
Configuring Fault Suppression for a Server
Configuring Fault Suppression Tasks for a Blade Server
Step 1 In the Navigation pane, click the Equipment tab.Step 2 ...
Yes you can, by disabling call home
Disabling Call Home
Step 1 In the Navigation pane, click the Admin tab.Step 2 On the Admin tab, expand All > Communication Management > Call Home.Step 3 In the Work pane, click the General tab.Step ...
As per the below document, your understanding is correct
Supported Software Release for Upgrade
To Software Release
4.2(1)SP1(3)—Minimum required version for Upgrade
4.2(1)SP1(6.2) and later releases
4.2(1)SP1(5.1) or 4.2(1)SP1(5....
For Interop you could refer:
For upgrading UCS: (choose according to your release)
Ok that's good.
Can you follow the below action plan and let us know how it goes
1. Modify vnic 1 to go through the same path as vnic 0, so both of them must be going out through the same IOM and FI. Now remove vnic 0, do you still have connectivity ...