Hi again, Still working on this one. When I rsync/ssh a big file to my server over the local network (100Mbit/s) with the --bwlimit=1000 I only have a small CPU load. SSH takes about 10% and rsync approximately 0-5%. In the end the transfer speed usually is around the value I set in bwlimit.
When I transfer the same file to a remote machine, where the bandwidth is limited to roughly 140KB/s and the bandwidth limit is set to something below this value I get around the same values which I have on the local network, SSH 10% and rsync somewhere between 0-5%. If I change the bwlimit value to 150KB/s or higher the SSH load goes up to 70% and rsync to 30% fully consuming my CPU. I think the problem is pretty clear now. Does anybody have an idea, what the next step could be to the resolution of this ? Regards, Jan -----Oorspronkelijk bericht----- Van: Jan Alphenaar [mailto:jan.alphen...@dotcolour.com] Verzonden: woensdag 17 februari 2010 12:17 Aan: 'rsync@lists.samba.org' Onderwerp: RE: Rsync / ssh high cpu load Hi, In an attempt to narrow this down a bit I installed a RedHat machine with openssh-5.3p1 and rsync-3.0.7 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 say that this is caused by the cygwin layer. I will mention this in the cygwin list. Still, if anybody has any ideas how to solve the issue below, please let me know. Warm regards, Jan -----Oorspronkelijk bericht----- Van: Jan Alphenaar [mailto:jan.alphen...@dotcolour.com] Verzonden: dinsdag 16 februari 2010 17:31 Aan: 'rsync@lists.samba.org' Onderwerp: Rsync / ssh high cpu load Hi everybody, I am using Cygwin rsync/ssh to synchronize my files from my home computer to my server. I raised a question on the Cygwin list as well, but thought this list would be appropriate too. The issue is that the CPU on the sending side is fully allocated by rsync/ssh (both taking 50%) during a file transfer. This is the command I use: rsync -e ssh * <user>@<server>:/data After some more testing on this I 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. Note this is the first install, the /data directory on the receiving side is empty. 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 (without cygwin), see what that gives me. Note that I am using these versions: Cygwin: 1.7.1-1 ssh: OpenSSH_5.3p1 rsync: 3.0.6 Has anybody seen this before ? Thanks in advance. Regards, Jan -- Please use reply-all for most replies to avoid omitting the mailing list. To unsubscribe or change options: https://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.catb.org/~esr/faqs/smart-questions.html