Shared folder for stream

We connect our FMS3 with our SAN using shared folders, the path to the shared folder is "\\.host\Shared Folders\SAN1\". And we tried to make this shared folder as "Z:" drive, then modified Application.xml as "<Streams>/;Z:\vod</Streams>", but the stream still would not play with error "ConnectionError". we also tried to modify Vhost.xml, still no luck.

We configure the SAN permission for FMS to read only, do we need to change it to Read&Write?

I am appreciate any possible solutions. Thank you.