Windows KVM defrag on shared storage?

I run mostly windows KVMs on my proxmox cluster all from a SAN (MD3200i) - is it worth running regular defrags on these KVMs as they are really all loaded up from 6 disks in the SAN anyway? Surely the data pattern on the virtual disk once its been separated across a RAID array and then a virtual disk, would already be fragmented accross the array/physical disks?

Physical Disks <--> RAID ARRAY <--> Virtual Disk <--> KVM Disk <--> Windows

Also would running something like diskkeeper (constant disk defrag) cause any issues with running KVMs - i expect having several copies running across our P2V converted machines wouldnt help (am trying to improve the disk performance as best as i can)

We recently moved from a ReadyNAS 2100 to a MD3200i - massive improvement anyway but just seeing if there is anything else i can do to squeeze any more performance - am running all servers in IDE with writeback enabled and getting over 550MB/s reads/writes.

Lost a server (thank goodness for backups ;)) after trying virtio using the .52 drivers (we're running mainly W2003 atm - slowly replacing them with 2008 R2 boxes) so not to happy about trying virtio again - athough saying that i have a couple of boxes using an older version (.49) and they're working fine in my test cluster.