We're seeing the exact same results as above on our end as well. nfsstat -d is flagging Windows 2K8 R2 boxes as generating misaligned IO whereas mbrscan says that everything is aligned. Being that I know that the 2008 R2 boxes are ok and that mbrscan is giving the results that I would expect, I'm not sure how to read or trust the nfsstat output.
Files Causing Misaligned IO's (nfsstat -d) and mbrscan don't agree
you can use vol read_fsid to find out which flexvol has that FSID
netapp01*> vol read_fsid customer01_oralogtemp
Volume 'customer01_oralogtemp' has an FSID of 0x17383d29.
Plus, you can have aligned VMs, but still have applications that generated non-aligned writes.
the example below is for an oracle database on NFS, all writes are aligned (it's NFS), but the writes to the redo logs can be for any size between 512b to ..... In this case, the writes can fall through a block boundary.