rsync writefd_unbuffered failed to write error

[vgnheart]

" DC does have a network wide firewall to guard against DDoS" then there is a chance of blockade by DC router. contact them and ask if they block any traffic from your server.

Also rsync can work in two method.

1) Download from remote server and save on local server
or
2) Upload from local server to remote

Which method you used. give a try on other method.