Question: I am looking to back up several Linux machines to a local Windows machine.

The machine resides on a LAN behind a router connected to a high-bandwidth cable modem with a static IP address. I can configure the router for port forwarding, if necessary.

I am currently exploring using rsync, specifically [cwRsync][1], to perform this backup. I have some questions:

1. When using rsync, which machine is the "server" and which is the "client"? Is the backup source the client and the backup destination the server, or vice-versa?
2. A cwRsync FAQ page hints that an OpenSSHD service should be running on a Windows machine for that machine to be able to be sent files via rsync. If OpenSSHD is truly needed, then which specific distribution or version do you recommend?
3. Can you think of a simpler and more effective way to effect this backup? I've used rsync across Linux machines with little trouble before, but it seems that getting this to work with a Windows machine involves quite a bit more work.

Thank you for your help!

Answer: 
1. It doesn't matter
2. No, you don't need an ssh server to use rsync as a client
3. I'd just run rsyncd on all the Linux machines, and cygwin on the Windows machines and write a script on Windows (maybe a cron job too) to get the files off the Linux machines.
If you are running the rsync process on the Windows machine with cygwin installed, than you don't need to install OpenSSHD on that Windows server to receive backups. You would only need to install this if you were intending on initializing the backups on the remote linux servers.