I recently installed a Dell SCV2020 SAN using iSCSI at my workplace and as part of the troubleshooting tested the failover as per the installation guidelines.

I basically disabled a NIC whilst doing a transfer and the guide said the transfer shouldn't be interrupted however it did pause for a good minute or so.  I can't recall whether I gave up and reenabled the NIC and found it continued or if it eventually continued itself in hindsight but I'll be doing some more testing myself tomorrow.

In any case I was hoping to get some advice on MPIO and what exactly I should be expecting of it.  To give you an idea of the setup; I have 2 Dell N2024 Switches each representing their own Fault Domain and each Fault Domain has a connection to each of the controllers on the SCV2020 (it has a second controller for redundancy). And each server has 2 connections (one to each switch).

Each HBA shows as having effectively 4 connections (2 from each Switch) and MPIO is enabled in the OS (Windows Server 2016) and listed as Round Robin.  I've confirmed the fail of a controller continues uninterrupted and expected the same to happen when disconnecting the paths.  Just incase disabling the Nic Port in the OS caused a problem I did it via the switch too (I couldn't be there to physically unplug it as I was working remotely) and encountered the same behaviour.

In my investigations I've discovered a couple timers around keepalive and iSCSI command but, from what I can see, the Dell guidance is to keep these unchanged.

So I guess ultimately my question is, is this the expected behaviour or should it not pause the transfer of the file at all?

Any advice would be greatly appreciated.