Thanks for your respone. i've discovered this paper on Netapps Library, but is was written in Feb this year and I normally understand the concept of Metro Cluster.
But What I specifically aould liek to know is, if when locally attached SAS Disks will be used, if the also can be used for Replication through the Filer and SyncMirror to the opposite Filer and the other sides SAS Disks.
I don't beleive that this will work, but it's not mentioned anywhere.
I just want to save money and use the cheaper disks and shelfs insted the old fashioned FC/SATA DS14.