I have six 500GB SSD drives in Raid-5 using LSI 9271-8i Raid Card. This server is running Window 2012 Hyper-v, it will host about 20 VMs. The default stripe size is 256KB, should I use larger size like 1MB?
As usual, to answer this question you should ask yourself what stripe size is and what does it impact to:
My usual choice is large chunks (stripes) and I think for "20 VMs" scenario it should be exactly the same.