On Tuesday 13 March 2007, Anders Johansson wrote:

Am Dienstag, den 13.03.2007, 09:50 -0900 schrieb John Andersen:

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I just copied a 350meg iso across 100mbit network via samba in under 10 minutes. It pegged my linux nic at 7.4 meg for the duration according to gkrellm.

I normally see 10M traffic in gkrellm when I copy stuff to and from my nfs server

All the more reason to suspect the OP has network problems. But I have slow disks. Perhaps thats why 7.4 was the fastest my gkrellm showed. Heck, one of my machines was an ancient dual celeron and I still was faster than his reported results. And my switch, while saying 10/100 on the front can not necessarily sustain that packet forwarding rate for long durations. You'd be amazed (or perhaps you wouldn't) how often a supposedly 100meg switch can not actually manage that transfer rate for more than a brief periods.

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So i would put that file on flat disk space (no raid) and copy it with samba to see if the problem is in the disk or the network. You definitely want to get sftp out of the picture.

Two comments to this: first of all, it would have exactly no effect on the data seen in e.g. gkrellm (unless you have very slow cpus), since it measures bits on the wire, not data received by the application

Not sure what that has to do with it. I timed this movement by my watch, not gkrellm.

Secondly, don't be so quick to discount ssh file transfers. It is heavy on the cpu, but it can even be quicker than plaintext to transfer data if the cpu can keep up. The encryption also does some level of compression, and I haven't been disappointed by the performance so far

How much compression would you expect on an iso? Have you tried to move a 650meg iso across nfs, and then do the same move across ssh from and to the same source/destination? I think you will find that on local networks where nothing is less than 100meg that ssh is quite a bit slower than a well tuned nfs. Samba is supposedly not as fast as nfs, but I've found it still is pretty swift compared to ssh transfers. -- _____________________________________ John Andersen

On Tue, 2007-03-13 at 16:17 -0500, Sunny wrote:

On 3/13/07, John Andersen wrote:

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I think you will find that on local networks where nothing is less than 100meg that ssh is quite a bit slower than a well tuned nfs.

As you said the magic word "well tuned nfs" ... :)

Please, define well-tuned. Or direct me to a very nice tutorial for this. I found a bunch all over the place, and I have very bad experience with the nfs performance while writing to nfs volumes. Very often it stops the transfer for some seconds, konqeror reporting "Stall" and then resumes. The last part of the file usually takes along time, etc. These observations are made using konqueror, midnight commander, and pure cp from commandline. Sometimes even the overall responsivness of the machine is lost (and this is 3400+ amd with 2G).

The files in question are usually more than 300M, and they start pretty well, but after the first 50-70 MB it starts to stall. I found out that using sftp takes about the same amount of time, but does not hog the mouse movement or window switching, as nfs write does.

I would suspect that this has to do with file system caching. The file won't be saved to disk straight away, but to memory. When the memory fills up, it will flush to disk. Does it make a difference if the box has just been rebooted compared to when the box has been up and running for a while? The sftp would be a bit slower generally as it is encrypted, so the target machine will not be hammered, thus being able to flush to disk without you noticing.

-- Svetoslav Milenov (Sunny)

Cheers, Magnus -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org

On Tuesday 13 March 2007 21:14, John Andersen wrote:

Have you tried to move a 650meg iso across nfs, and then do the same move across ssh from and to the same source/destination?

I think you will find that on local networks where nothing is less than 100meg that ssh is quite a bit slower than a well tuned nfs.

Just in case you're still interested, I'm doing this now, and I'm getting a constant data rate of over 10MB/s (in real data, not bits over the wire). This means a 100MB file transfers in 9 seconds, or 1024MB in 1 minute 34 seconds. All using scp -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org

On Thursday 15 March 2007 06:48, John Andersen wrote:

On Wednesday 14 March 2007, Anders Johansson wrote:

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Just in case you're still interested, I'm doing this now, and I'm getting a constant data rate of over 10MB/s (in real data, not bits over the wire). This means a 100MB file transfers in 9 seconds, or 1024MB in 1 minute 34 seconds. All using scp

I don't doubt that Anders, that performance is quite acceptable.

My point was, that without testing a samba or nfs transfer you have no way of judging the load imposed by scp.

There is a substantial CPU load, to be sure. My 2GHz Celeron was at ~75% throughout the transfer. A slower CPU would have spiked, causing a slowdown in the transfer

The OP did those tests, and his 35minute transfer with ssh dropped to 5 minutes. He suspects a faulty ssh client, as do I, because that much difference it way out of line with what I would expect.

Could be. But I'd be interested in knowing what hardware is involved, and what the system load looked like during the transfer -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org

trouble of setting up an NFS mount (and then dealing with processes hanging in the D state every time the server is down.) -- I use rsync and ssh to backup our home directories and the initial

But scp is so convenient for doing copies compared to the transfer of my folder was about 2.0+ GB and (I am not completely sure of the time) less than 5 minutes to transfer. I will time the next complete transfer. note: That transfer was from two different laptops to the lan by way of wireless connection. -- John Registered Linux User 263680, get counted at http://counter.li.org -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org