I've heard and read that for various reasons, NAS is slower than SANs for applications that use an SQL DB for their underlying structure.
If you are using SQL with NAS I'm told, the I/O needs to be translated to the TCP/IP stack, which creates enormous latency since every packet has to be translated. Add this latency to the additional latency from reordering the packets and performance can suffer dramatically, just because the wrong connectivity was used.
Everything else being equal, what is the real truth?
This was first published in May 2001