gigabit connection to nas not working?

weltio · 2016-04-26 18:29:56

I have a nas and a desktop pc with two networkinterfaces. Both support gigabit ethernet. My router only supports 100mbit/s.

On both machines:

cat /sys/class/net/eth0/speed
1000

so i used basically this command to benchmark the connection:

down_speed=`scp -v $ssh_server:$test_file $test_file 2>&1 | \
  grep "Bytes per second" | \
  sed "s/^[^0-9]*\([0-9.]*\)[^0-9]*\([0-9.]*\).*$/\2/g"
down_speed=`echo "($down_speed*0.0009765625*100.0+0.5)/1*0.01" | bc`

I built three different topolgies

1: nas <-> pc
2: nas <- gigabit-switch -> pc // and the switch is connected to my router 100mbit
3: nas <- router -> pc (for reference)

tragically, all setups return an approximate down_speed value of 6484.28 kB/s.
At least 1: should be faster than 3: - actually I would think, 2 would be almost as fast as 1:

What could be a reason for this?
could the cable be responsible?

Last edited by weltio (2016-04-26 18:52:30)

graysky · 2016-04-26 19:00:26

Firstly, I recommend a more functional test of transfer speeds; see this post and the script therein for throughout testing purposes. Secondly, you probably want to add an unmanaged GBit switch into your mix to allow for the GBit xfer speeds.

modem <--> router <---> switch --->PC
                           |
                           --------->NAS

Last edited by graysky (2016-04-26 19:03:15)

alphaniner · 2016-04-26 19:06:39

First off, what's wrong with the values reported by default?

$ scp server:/somefile .
somefile                    100% 3166MB 113.1MB/s   00:28

R00KIE · 2016-04-26 19:47:53

Doesn't scp use encryption via ssh? NAS boxes are usually not very powerful cpu wise so I'd avoid anything that might tax the cpu when testing transfer speeds.

graysky · 2016-04-26 20:03:01

@alphaniner - Drawing conclusions based on 1 measurement is ill-advised. Replicates, means, and standard deviations around data sets give me far more confidence.
@ROOKIE - Yes, this is a good point. So long as the default cipher doesn't saturate the CPU he should be fine.

The key point of my post is the recommendation to add an unmanaged GBit switch... a 5-port (netgear) on amazon is only $20 so it's tough to go wrong I can recommend these guys as rugged, fast, and good longevity.

Last edited by graysky (2016-04-26 20:03:48)

alphaniner · 2016-04-26 20:27:08

@graysky I started that post before you posted yours (got sidetracked) and simply meant it as an alternative to the crazy pipe machination OP is using in case of mathematical errors.

Also in regards to your first post, is OP's configuration 2 not identical to your suggestion of

modem <--> router <---> switch --->PC
                           |
                           --------->NAS

graysky · 2016-04-26 21:37:34

@alphaniner - I must have memory problems. I didn't see that when I read the first post <<red face>>

Arch Linux

#1 2016-04-26 18:29:56

gigabit connection to nas not working?

#2 2016-04-26 19:00:26

Re: gigabit connection to nas not working?

#3 2016-04-26 19:06:39

Re: gigabit connection to nas not working?

#4 2016-04-26 19:47:53

Re: gigabit connection to nas not working?

#5 2016-04-26 20:03:01

Re: gigabit connection to nas not working?

#6 2016-04-26 20:27:08

Re: gigabit connection to nas not working?

#7 2016-04-26 21:37:34

Re: gigabit connection to nas not working?

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