I have done it from home... (MD3000i)   Make sure the machine you are remoting into with MDSM on it is not running off the storage.   I made that mistake only once.  I leave the ESX / ESXi hosts running but shut down the VM's.   The controllers get reset, as in basically powercycled by the updating,  I can't believe any VM would survive through that if left powered on. 
I have a dual-controller MD3200 (plus a slaved MD1200) which is running firmware v07.70.06.63 and NVSRAM vN26x0-770890-005 and I need to upgrade both the firmware and the NVSRAM to take advantage of some new features.  I am also about to implement the High Performance Tier and another MD1220 tier of storage. Wondering if anyone has experience of firmware and/or NVSRAM upgrades on the MD3200 dual-controller device? From reading the upgrade notes, it seems like it should be possible for me to upgrade without having to shut down my VMs, however this strikes me as overly optimistic.  So I intend a planned systems outage, will shut down the VMs, then upgrade and restart all the VMs once the firmware is upgraded and the storage array is visible from my ESXi hosts. Any thoughts or experiences that anyone can share?  e.g. will I need to physically reboot (power off and on) the storage arrays?  I was hoping to do most of this work from home and would like to avoid having to physically attend on site if I can.
Firmware and NVSRAM upgrades on dual-controller MD3200