[CentOS] BackupPC and rsync

Thu Sep 27 02:25:11 UTC 2012
Gordon Messmer <yinyang at eburg.com>

On 09/25/2012 08:33 PM, Emmett Culley wrote:
> Since then backups have been failing for some targets.  The failure
> is a TCP ZeroWindow issue.  It looks like the server rsync process
> cannot empty it's buffer soon enough and eventually the process
> fails.

If the rsync server sends a TCP ZeroWindow packet to a client, that 
probably indicates that the server is either hung or looped.  Either 
way, it has stopped reading data from the socket, and the kernel sends 
ZeroWindow to the client's host to indicate that the client should stop 
sending data.

You may have found a bug in rsync that the developers need to resolve. 
Have you tried attaching strace to the rsync server process when it hangs?