Hi Ethan,   Unfortunately Meraki switches do not support breakout cables to divide a 40Gb port into four 10Gb ports.  They also do not support the single adapter that does the same.   For the SAN connection you can use 10Gb RJ45 adapters, but there is no Meraki / Cisco part, so you need a third party one.  I have had good experience with the FS ones that mimic a Cisco 10Gb SR fibre adapter, but buy one first to make sure that it fits in the MS425 as I had issues in the SFP+ ports on the MS355, but not those on an MS225.    The SAN does have the option to be specified with SFP+ ports as opposed to RJ-45 and I would recommend that if you are buying more as you can then use DAC cables and if you need RJ45 then the above FS adapters work well in those SANs.  Don't be tempted to order the adapters with a Dell code in them as they will not work... ... View more