X-Recipient: archive-cygwin AT delorie DOT com X-SWARE-Spam-Status: No, hits=2.4 required=5.0 tests=AWL,BAYES_00,RCVD_IN_SORBS_DUL,RDNS_DYNAMIC,TVD_RCVD_IP X-Spam-Check-By: sourceware.org From: "Jan Alphenaar" To: Subject: FW: Cygwin Rsync/SSH performance issue Date: Wed, 17 Feb 2010 12:26:45 +0100 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-IsSubscribed: yes Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com Delivered-To: mailing list cygwin AT cygwin DOT com Hi At first this email was sent to the developers list, but I understood this list is more appropriate. Regards, Jan -----Oorspronkelijk bericht----- Van: Jan Alphenaar [mailto:jan DOT alphenaar AT dotcolour DOT com] Verzonden: woensdag 17 februari 2010 12:25 Aan: 'cygwin-developers AT cygwin DOT com' Onderwerp: RE: Cygwin Rsync/SSH performance issue Hi, In an attempt to narrow this down a bit I installed a RedHat machine with openssh-5.3p1 and rsync-3.0.7 (thus without cygwin) and did the same test as below. Transferring data, both up and downstream, are not giving me any CPU load. Although there is a small version difference in the rsync versions, I would conclude that this is somehow caused by the cygwin layer. If anybody can have a look at it, I would really appreciate it. If there is something I can do, please let me know. Warm regards, Jan -----Oorspronkelijk bericht----- Van: Jan Alphenaar [mailto:jan DOT alphenaar AT dotcolour DOT com] Verzonden: dinsdag 16 februari 2010 16:46 Aan: 'cygwin-developers AT cygwin DOT com' Onderwerp: RE: Cygwin Rsync/SSH performance issue Hi again, I did some more testing on this and figured out that rsync/ssh is only taking the full cpu if the bandwidth allocated to the session exceeds the true bandwidth available on the link. For example, if the uplink is 128KB/s and I pass in the --bwlimit=24 parameter the cpu is around 0%. Even --bw-limit=126 does not take 100% cpu, but --bwlimit=132 does. Would this be because of packet loss on the link and packets have to be retransmitted ? I will do a quick test tonight with rsync/ssh between two linux boxes, see what that gives me. Regards, Jan -----Oorspronkelijk bericht----- Van: Jan Alphenaar [mailto:jan DOT alphenaar AT dotcolour DOT com] Verzonden: dinsdag 16 februari 2010 11:34 Aan: 'cygwin-developers AT cygwin DOT com' Onderwerp: Cygwin Rsync/SSH performance issue Hi everybody, I am using rsync/ssh to copy files from my computer to my server and everything seems to function as expected, except performance. During a file transfer on my home computer (Intel I7) there is not a noticeable CPU load. But on other (older) machines the rsync/ssh transfer consumes all CPU resources on the sending side. I noticed there are other questions regarding this subject in the archives, but I could not find a solution for this. Also throttling the bandwidth to a lower value is not helping to reduce the CPU load. I am using quite a basic command to sync my files: rsync -e ssh * @:/data The versions of the software I am using are: Cygwin: 1.7.1-1 ssh: OpenSSH_5.3p1 rsync: 3.0.6 OS: WinXP Was anybody able to resolve this ? Any help is greatly appreciated. Warm regards, Jan -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple