The following article lists the A/V (Anti-Virus) exclusion maskings for files used by MED-V.  In order to prevent antivirus activity from affecting the performance of the virtual desktop, it is recommended to exclude the following Virtual Machine file types from any antivirus or backup processing running on the host:

*.VHD - These represent the Virtual Hard Disk Image files. These will appear on test workstations when test images are being used to finalize workspace policies.

*.VUD - These represent Virtual PC Undo Disk Files. These will appear on test workstations when test images are being used to finalize workspace policies.

*.VSV - These represent Virtual PC Saved State files. These will be on all MED-V clients running Workspaces.

*.CKM - This is the packed image format used by MED-V (Kidaro Compressed Machine.) These will be present on MED-V Servers, Image Distribution Servers, locally packed images on MED-V Administration workstations, and as pre-staged images on clients.

*.VMC - These represent the Base Virtual Machine Settings File. Will be found on all MED-V Clients and Test Workstations.

*.INDEX - These are index files used by the TrimTransfer Feature. These will be found on both clients and servers.

*.EVHD - These are the encrypted virtual hard disk files used on MED-V Clients running workspaces.

Note: This information was originally contributed by Steve Thomas, Senior Support Escalation Engineer, on the MED-V Team blog:

http://blogs.technet.com/medv/archive/2009/05/28/recommended-anti-virus-exclusions-for-med-v-client-workspace-installations.aspx