Performance Issue Need Advice

[davida]

Hello, I am new to building a NAS and have built one using a Dell poweredge 430 with 2 western digital 2TB and 80G with Ubuntu.

I am getting less that 7MB/sec on iperf and really need some advise to steer me in the right direction

 

[davida]

Found a big change by not using belkin router. Using a netgear gs205 speed increased to 35MB/sec. Would be great to get toward 80.

 

[TonyH]

Hi,
Are you talking about Megabit or MegaByte?

 

[Terry Kennedy]

Hello, I am new to building a NAS and have built one using a Dell poweredge 430 with 2 western digital 2TB and 80G with Ubuntu.

I am getting less that 7MB/sec on iperf and really need some advise to steer me in the right direction

iperf measures network performance only - it doesn't involve the hard drive(s) at all.

Which exact PowerEdge 430 model are you using? I see a SC 430 which seems to be an older system (the Dell spec sheet for it was last updated in 2005). It probably has a decent network chip (from the downloadable drivers, either a BNX or a BNXII).

You can remove all of your network hardware from the equation by running iperf on the loopback interface. Here's how I do it on FreeBSD:

(1:12) host:/usr/ports/benchmarks/iperf/work/iperf-2.0.5/src# ./iperf -B 127.0.0.1 -s
------------------------------------------------------------
Server listening on TCP port 5001
Binding to local address 127.0.0.1
TCP window size: 64.0 KByte (default)
------------------------------------------------------------
[  4] local 127.0.0.1 port 5001 connected with 127.0.0.1 port 52602
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec  2.32 GBytes  1.99 Gbits/sec

(0:2) host:/usr/ports/benchmarks/iperf/work/iperf-2.0.5/src# ./iperf -c 127.0.0.1
------------------------------------------------------------
Client connecting to 127.0.0.1, TCP port 5001
TCP window size: 42.0 KByte (default)
------------------------------------------------------------
[  3] local 127.0.0.1 port 52602 connected with 127.0.0.1 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  2.32 GBytes  1.99 Gbits/sec

This will exercise the TCP stack and your kernel, but nothing else. You'll get higher speeds than you will see when running on a real network interface, but it is a good "what if" test to make sure there isn't something horribly wrong.

BTW, the above tests were done on a PowerEdge 750 (Pentium 4 3.4GHz, 4GB of RAM). Modern hardware will be much faster. This is on a PowerEdge R710, again using the loopback interface:

0:398) host:~terry# iperf -c 127.0.0.1
------------------------------------------------------------
Client connecting to 127.0.0.1, TCP port 5001
TCP window size: 42.0 KByte (default)
------------------------------------------------------------
[  3] local 127.0.0.1 port 61705 connected with 127.0.0.1 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  24.9 GBytes  21.4 Gbits/sec

Of course, using actual hardware things will be somewhat slower - here's a test between two of my homebrew NAS boxes (connected via 10Gbit/sec Ethernet):

(0:187) server1:~terry# iperf -c server2
------------------------------------------------------------
Client connecting to server2, TCP port 5001
TCP window size: 32.0 KByte (default)
------------------------------------------------------------
[  3] local 10.20.30.40 port 40242 connected with 10.20.30.41 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  11.0 GBytes  9.44 Gbits/sec

[Addresses and hostnames changed, but they really do get "wire speed" on 10GbE.]