While LAN-free and server-free backup will lessen impact on LAN resources and server/LAN resources, respectively, neither solution will eliminate the physical limitations of disk subsystems and tape subsystems. Rick Cook describes, "While LAN-free backup may not tax servers of LANs, it still requires storage system resources and the use of the SAN channels. The Gartner Group pointed this out in a recent research note discussing the concept, which it called 'outboard backup'. Like any backup process, outboard backup will generate intense I/O activity that can saturate disk devices, disk subsystems and channel connections. Application performance will be affected when application I/O is in competition with an outboard backup process. Another difficulty, the report notes, is the need for standards for server-less backup, so that the hardware, storage and infrastructure components can interoperate." [Reference 2] Both LAN-free and server-free implementations will face these issues, as SAN implementations grow more complex and diverse in function.
Current implementations of server-free backup also require the use of 'data mover' SAN routers. While this technology is certified with specific application vendors, these solutions have not announced compliance with leading manufacturers of SAN fabric and SAN devices.