Why is rsync a problem? Where is the bottleneck in the protocol or the code implementing it? Specifics! SAR is antiquated doesn't give the info you really need. Using a linux system? Use procallator and feed resulting collected data to ORCA. Better yet, use DTrace or at least truss. Compile rsync with profiling code -- use Sun Studio 12 it runs on Linux as well as Solaris and its a free download.
From a network protocol perspective rsync is quite good. If your network capacity is so large that it exceeds bandwidth or IOPs of your disks you probably can afford better disks or a more efficient disk storage layout. Are mirrors like nic.funet.fi running multiple gigabit WAN connections? If so they could sure demand stream more than a bunch of SATA2 disks can provide. Without performance data its a waste of time to argue against rsync Sent from my BlackBerry® smartphone with Nextel Direct Connect
