[CentOS] Rsync/SSH automation problem?

Fri May 1 17:09:51 UTC 2009
Les Mikesell <lesmikesell at gmail.com>

Gordon Messmer wrote:
> 
>>> The second thing you will notice, eventually, is that rsync over ssh 
>>> under Cygwin is unreliable.
>> You mean *starting* an rsync operation on that side? Using rsync over ssh 
>> essentially uses rsync on *both* ends. So, it's running under Cygwin, anyway, 
>> which makes your statement a bit confusing.
> 
> What I mean is that if you launch rsync with something like:
> 
> rsync -e ssh server:/path /path
> 
> then rsync uses a non-blocking (I said blocking earlier, which was a 
> mistake) socket pair to communicate with ssh.  This may trigger a bug in 
> cygwin which can cause the application to hang.

It always seemed to work when you execute the command on the windows 
side but had a bug that would hang when windows was on the answering 
side and started rsync under sshd.

> If, instead, you run rsync as a daemon on Windows, you can reliably 
> communicate with the daemon over TCP.  This remains true if you use ssh 
> to forward a port.  Thus, I recommend that anyone running rsync on 
> Windows set up rsync as a daemon that listens for connections on 
> localhost only and use ssh port forwards to reach it from remote systems.

I think the sshd issue is fixed in the current cygwin but another bug in 
rsync can cause problems with certain windows paths unless both ends are 
newer than 2.6.9 and support protocol 30 (Centos ships a 2.6.8).

-- 
   Les Mikesell
    lesmikesell at gmail.com