Accroding to the help rsync --daemon -h the daemon should work with --bwlimit.
Unfortunately --bwlimit does not work.
It only works as a client option, but not on the server side:
# rsync --daemon --bwlimit=100
I'm transferring a 10MByte file over network.
It looks like the function is not implemented for the --deamon mode. Can somebody confirm this?
The --bwlimit option is understood when starting the daemon, but the value isn't shared with the client, so any limiting that the client side would normally be in charge of won't happen. If you're wanting to force --bwlimit to a particular value, your only option is probably to write a pre-xfer exec script that scans the args and dies with an error if bwlimit isn't right.
What we need to do for the future is make the daemon side send any in-effect bwlimit to the client in the protocol at startup.