On 08/31/2019 01:28 PM, Carlos E. R. wrote:
On 31/08/2019 05.36, Lew Wolfgang wrote:
....
I tested scp against rcp in my admittedly limited use case, and found that scp ran at about 50% of rcp's speed (IIRC). Granted, a limited use case, but valid nevertheless. Depending on what my users are doing, rcp saves them, literally, days of time. Yes, they use rsync too, and specify rsh instead of the default ssh for the remote shell.
Why the speed difference? I assumed it was scp's encryption, but I admit it could be other things. It doesn't matter, it is what it is, and I can't use classic rcp starting with Leap 15. Ergo, this thread. Maybe you hit the speed difference because your network is so fast, and ours is not. Interesting!
My test was with direct 10-GbE nic-to-nic connections. No switch was in the path. The machines were server-class Supermicros, with Intel nics.
Small test here:
cer@Telcontar:~/tmp/ssh> scp cer@isengard:Laura01.mp4 . Laura01.mp4 100% 472MB 42.5MB/s 00:11 cer@Telcontar:~/tmp/ssh>
Well, it is a gigabit network, it should be twice as fast. One CPU core goes almost 100% on both server and client, so the app is expensive and doesn't maximize network speed. Let's try using the rsync daemon instead.
cer@Telcontar:~/tmp/ssh> rsync --stats --password-file=/home/cer/Cripta/keys/rsync.secrets cer@Isengard.valinor::Videos/Stratton.mpeg .
Number of files: 1 (reg: 1) Number of created files: 1 (reg: 1) Number of deleted files: 0 Number of regular files transferred: 1 Total file size: 8,058,862,896 bytes Total transferred file size: 8,058,862,896 bytes Literal data: 8,058,862,896 bytes Matched data: 0 bytes File list size: 39 File list generation time: 0.001 seconds File list transfer time: 0.000 seconds Total bytes sent: 43 Total bytes received: 8,060,830,473
sent 43 bytes received 8,060,830,473 bytes 89,069,950.45 bytes/sec total size is 8,058,862,896 speedup is 1.00 cer@Telcontar:~/tmp/ssh>
Ie, 89MB/sec, about double the speed.
That's interesting! I wonder what shell you're using? openSUSE's rsync defaults to ssh, right? So rsync and rcp should be about the same, I'd think. I'll have to fiddle around some more.
Why can't you use rcp? Maybe you said it and I missed or forgot.
cer@Telcontar:~> rcp If 'rcp' is not a typo you can use command-not-found to lookup the package that contains it, like this: cnf rcp cer@Telcontar:~> cnf rcp
The program 'rcp' can be found in the following package: * mrsh-rsh-compat [ path: /usr/bin/rcp, repository: zypp (download.opensuse.org-oss) ]
Try installing with: sudo zypper install mrsh-rsh-compat
cer@Telcontar:~>
So it is in another package that I have not installed. Doesn't it work? Or is it that it uses some new authentication method you don't like, that munge thing?
Yes, the munge thing is required in Leap 15 and up. I was using standard rsh before.
About ssh. I understand that Anton says that cypher none exists but is not listed. So I tried:
cer@Telcontar:~/tmp/ssh> scp usage: scp [-346BCpqrTv] [-c cipher] [-F ssh_config] [-i identity_file] [-l limit] [-o ssh_option] [-P port] [-S program] [[user@]host1:]file1 ... [[user@]host2:]file2 cer@Telcontar:~/tmp/ssh> scp cer@isengard:messages . messages 100% 2642KB 33.5MB/s 00:00 cer@Telcontar:~/tmp/ssh> scp -c none cer@isengard:messages . Unknown cipher type 'none' cer@Telcontar:~/tmp/ssh>
This is what I saw too. There are still some mysteries lurking about here somewhere... Regards, Lew -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org