cPanel Server - Slow Network Speed

[fidividi]

Hello,

We are running below machine:
CLOUDLINUX 6.5 x86_64 standard – HOSTNAME WHM 11.42.1 (build 16)

Our datacenter is Hetzner.

Throughout all the tests we performed, we thought the issue is with datacenter. So we reported the low speed to Hetzner, they claimed there's no limit, so they asked us to take our machine down in their rescue mode linux environment, and we provided them couple of links that we were experiencing extremely low speed (max: 3~5mbit/s), they tested the speed on our server, with no changes to the network configuration, but just in different environment than cPanel, and below is the result provided to us:

Dear Client,

We have checked the download speed via the rescue system:

-----------------%<-----------------
[email protected] ~ # wget http://speedtest.atlanta.linode.com/100MB-atlanta.bin
--2014-05-24 15:20:31-- http://speedtest.atlanta.linode.com/100MB-atlanta.bin
Resolving speedtest.atlanta.linode.com (speedtest.atlanta.linode.com)...
2600:3c02::4b, 50.116.39.117
Connecting to speedtest.atlanta.linode.com
(speedtest.atlanta.linode.com)|2600:3c02::4b|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 104857600 (100M) [application/octet-stream]
Saving to: `100MB-atlanta.bin'

100%[==============================>] 104,857,600 22.0M/s in 6.7s

2014-05-24 15:20:38 (15.0 MB/s) - `100MB-atlanta.bin' saved [104857600/104857600]



[email protected] ~ # wget http://ipv4.speedtest-nyc1.digitalocean.com/100mb.test
--2014-05-24 15:23:04-- http://ipv4.speedtest-nyc1.digitalocean.com/100mb.test
Resolving ipv4.speedtest-nyc1.digitalocean.com
(ipv4.speedtest-nyc1.digitalocean.com)... 198.211.112.36
Connecting to ipv4.speedtest-nyc1.digitalocean.com
(ipv4.speedtest-nyc1.digitalocean.com)|198.211.112.36|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 104857600 (100M) [application/octet-stream]
Saving to: `100mb.test.1'

100%[===============================>] 104,857,600 4.11M/s in 34s

2014-05-24 15:23:38 (2.94 MB/s) - `100mb.test' saved [104857600/104857600]



[email protected] ~ # wget speed.hetzner.de/1GB.iso
--2014-05-24 15:20:56-- http://speed.hetzner.de/1GB.iso
Resolving speed.hetzner.de (speed.hetzner.de)... 2a01:4f8:0:a140::2, 88.198.222.222
Connecting to speed.hetzner.de (speed.hetzner.de)|2a01:4f8:0:a140::2|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1048576000 (1000M) [application/octet-stream]
Saving to: `1GB.iso'

100%[===============================>] 1,048,576,000 95.9M/s in 11s

2014-05-24 15:21:07 (90.6 MB/s) - `1GB.iso' saved [1048576000/1048576000]
-----------------%<-----------------

So it seems that in the rescue system the speed is fine.

As I mentioned above, we are running cPanel with CloudLinux. I am not aware of any limitation/configuration where we can have such control over cPanel download/upload network speed, and same applied for CloudLinux.

What could the issue be?

We have noticed the speed can not max out more than 5mbit/second. Slow enough that account transfers never finish...

I appreciate any help!

Thank you.

 

[JayFromEpic]

The slow connection speed could be caused from a dozen of different causes. The server would need to be reviewed by a System Engineer capable of diagnosing network device/driver errors.

 

[dalem]

your testing is not consistent
you comparing a local download to remote

I get the same speeds from Linode 22.0M/s
From our servers in Las Vegas
so I don't think you have speed issue

 

[fidividi]

your testing is not consistent
you comparing a local download to remote

I get the same speeds from Linode 22.0M/s
From our servers in Las Vegas
so I don't think you have speed issue

I don't think you read my post in detail.

My issue is, basically in rescue mode, our server downloaded from Linode on average 2.94 MB/s, in cPanel/CloudLinux operating system, it can only reach 3~4mb/s, for the same exact file, almost within the same time-frame. There is almost 7~8 times difference...

This obviously tells me something is wrong with the setup, as our machine was able to download faster, much faster, while not in cPanel/CloudLinux environment.

 

[dalem]

No I did not sorry you only posted speeds from rescue mode I did not catch that.

Check your network stack
quick how too
Linux Tune Network Stack (Buffers Size) To Increase Networking Performance

and make sure you do not have anything running on the box that will restrict you packets
EG: Firewall, Iptables rules, Mod deflate, etc

 

[cPanelMichael]

Hello

Yes, I suggest making sure there are no firewall rules that could be limiting traffic. You are also welcome to open a support ticket so we can take a closer look and rule out any involvement with the cPanel/WHM software.

Thank you.