network speed throughput

[sdbhabal]

I have 1gbps ethernet controller on both the server, but when i am coping any files from one system to another, i am getting only upto 4mbps speed.
Kindly advise.
Thanks in advance....

[Irithori]

- What are the hardware specs of the two servers?
- Are they under (heavy) load?
- Which NICs are in use?

lspci |grep -i eth
dmesg |grep eth

- How are they connected? How many hops, are there gigabit switches?
- What method do you use to transfer files?
- How many files are there?

[sdbhabal]

Hi Irithori,

Please find following detail's (same for both server's)_
1. Hardware specification are as follows_
Intel(R) Core(TM)2 Duo CPU E7500 @ 2.93GHz
Memory : 4GB

2. Both are testing server's, nothing is there running on server which take much load.

3. Ethernet controller: Atheros Communications AR8151 v1.0 Gigabit Ethernet (rev c0)
atheros_eth 0000:03:00.0: ATL1C: eth0 NIC Link is Up<1000 Mbps Full Duplex>
eth0: no IPv6 routers present

4. They are connected on "HP ProCurve 1810G - 24 GE, P.1.17, eCos-2.0", only 1 hope count.

5. Any method cp, scp etc.

6. I ahve tried several files & folder's result is the same giving speed upto only 3-4mbps.

Regards
Santosh

[Irithori]

You can do a quick and dirty performance test with netcat (nc) and dstat

- Install these two packages: netcat, dstat

- Open two consoles on server A:
first:

nc -l 2000 > /dev/null

second:

dstat -n

- Open one console on server B:

cat /dev/zero | nc <IP_of_SERVER A> 2000

That will produce the max network throughput, that the tcp stack in your current configuration can do.
I would expect at least 90MByte/s here, and even more.

[sdbhabal]

Hi Irithori,

My server has 1gbps ethrnet controller.
Also on other side my switch also has 1gbps port configured.
But "mii-tool" produce "eth1: negotiated 100baseTx-FD, link ok".
why "mii-tool" showing like this.

Regards
Santosh

[Irithori]

mii-tool seems to produce false outputs.
I also experience this on my machines, and they are definitely 1GBit/s.
Your dmesg shows 1GBit/s

Could you perform the little netcat experiment?

[sdbhabal]

Hi Irithori,

As per your instruction i have done required testing.
Below is the result of "dstat -n" command_

-net/total-
recv send
71M 3551k
69M 3443k
74M 3659k
102M 5149k
102M 5166k
101M 5109k
102M 5130k
103M 5174k
103M 5198k
103M 5173k
102M 5131k
102M 5122k
102M 5135k
103M 5170k
104M 5243k
103M 5181k
102M 5163k
103M 5173k
103M 5178k
103M 5215k
101M 5103k
103M 5188k
103M 5186k
102M 5157k
103M 5196k
101M 5103k
102M 5116k
103M 5177k
102M 5150k
102M 5119k
102M 5140k
101M 5105k
101M 5089k
102M 5109k
103M 5168k
103M 5187k

What does it means? kindly explain.

Regards
Santosh

[Irithori]

That means, your network is not the bottleneck.
You get more than 100MByte/s.

I believe, you will get similar speed for rsync-ing or scp-ing big files over the network, like a ISO image.

A possible bottleneck is, if you try to copy many small files.
And/or if there is heavy processing (generating, compression, encrypting,..) before the actual copy.

As a next test, you could do a copy/rsync locally to another(!) drive and see how much speed you can get.
But I believe, your problem is IO bound.

[sdbhabal]

IO bound is something new for me.
what is this exactly?

[Irithori]

IO = disc performance.
That would be the next thing I would test.
And naturally many small files are slower.