Scan on ingest
Pro
- Easy to implement
 
Con
- New viruses won't be recognized
 
Recurring batch scan
Pro
- Easy to implement
 - Runs when the servers are idle
 
Con
- Scans unused files
 - Stresses local fileservers and uses bandwith for external resources
 
Scan on access
Pro
- Only scans what needs scanning
 
Con
- Hard to implement
 - Non-trivial realtime processing requirements