Windows 2003, Cygwin, and rsync

Christian Hack christianh at
Wed Jun 21 07:06:22 GMT 2006

> -----Original Message-----
> From: at 
> [ at] 
> On Behalf Of John Oliver
> Sent: Wednesday, 21 June 2006 7:11 AM
> To: rsync at
> Subject: Windows 2003, Cygwin, and rsync
> I just installed Cygwin / OpenSSH / rsync on two Dell PowerVault 745N
> NASes running Windows 2003 Appliance Edition.  My rsync daemons are
> running, ssh works, and in theory all is well.  But... I'm getting an
> average of maybe 15 Mb/s rsyncing between them.
> Now, I know I have an issue in the way they're connected... one is
> attached to a Cisco 2970 (1 Gb/s), which is attached to a NetGear
> 100Mb/s switch, which has the other NAS attached to it.  Yes, the
> NetGear is going to go away :-)  And the NASes are going to 
> wind up with
> a crossover cable between them for a straight, dedicated 1Gb/s  But it
> certainly looks like rsync is not using more than a fraction of the
> (theoretically) available 100Mb/s  There are several other hosts
> attached to the NetGear switch, and there is no "slowness" about them
> (which disproved my initial hypothesis of a saturated backplane)
> Is this a known rsync and/or Cygwin issue?
> I also get a "cannot send long-named file" message that halted rsync
> The file in question is probably a fluke, but this could happen again.
> How could I get rsync to just ignore the too-long filename, or maybe
> increase the limit of what it considers "too long"?

I have the long file name issue too, but it doesn't stop my rsync from
running. Windows is limited to (I think) 255 characters for the full path +

As for you speed issues. From a Dual Xeon 3.2GHz to a dual P3 1GHz (both
Win2k3 server) using a single 500MB file for transfer I was able to get
5.4MB/sec over a 100Mb LAN through at least 1 switch. Which is not too far
off the theoretical limit. That was from an active file server during the
middle of the day too.

Using the -W whole file option didn't really help although it might with
lots smaller files. Turning on compression (-z) didn't help either and
should probably be turned off over a LAN anyway.

Maybe try doing a simple file copy to see what throughput you can get

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