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Extremely Slow Network Speeds On Windows Guests

Posted: 11. Aug 2010, 15:10
by CarlosinFL
I have two servers on my Linux VirtualBox host:

- Windows Server 2003 (32-bit)
- Windows Server 2008 (64-bit)

The Windows 2003 Server appears to work good however when I try and copy files to and from it, the transfer speeds are awful / super slow. I checked the network adapter on the Windows side and it shows it's connecting at 1.0 Gbps. Is there anything I can check or do to find out why on the virtual side my Windows servers are super slow and time out...

*EDIT*

I verified my Linux host was not operating it's network card in degraded mode or something like that:

Code: Select all

carlos@vbox2:~$ cat /sys/class/net/eth0/speed
1000
carlos@vbox2:~$ cat /sys/class/net/eth0/duplex
full

Re: Extremely Slow Network Speeds On Windows Guests

Posted: 8. Oct 2010, 23:03
by cornbread
Same issues here. Very poor guest networking performance. 6-8 MBps should be 20+

Re: Extremely Slow Network Speeds On Windows Guests

Posted: 8. Oct 2010, 23:22
by Perryg
Windows is usually very conservative with its network throughput try seeing if you can manually adjust the MTU to 1500.
Also what network adapter are you using in the Windows guests?
You need to post one of the guests log file (as an attachment) too so we can see if there are any problems.

Re: Extremely Slow Network Speeds On Windows Guests

Posted: 24. Oct 2010, 19:58
by cornbread
Sorry was out of the country.

Now that I'm back. I have some info for you.

adjusted the MTU to 1500 did see slight increase.

Still haven't checked on gigabit connection to see what the speeds are but 100mb connection is 50+% slower than host.

Guest interface driver: Intel PRO/1000 MT Server

TIA for all the help

Re: Extremely Slow Network Speeds On Windows Guests

Posted: 24. Oct 2010, 20:13
by Perryg
@cornbread,
What version of VirtualBox are you using and is it OSE or PUEL?

Re: Extremely Slow Network Speeds On Windows Guests

Posted: 24. Oct 2010, 20:27
by cornbread
PUEL

Re: Extremely Slow Network Speeds On Windows Guests

Posted: 24. Oct 2010, 21:59
by Perryg
And the version?

Re: Extremely Slow Network Speeds On Windows Guests

Posted: 25. Oct 2010, 05:33
by cornbread
vbox 3.2.10 host is ubuntu lucid 64 bit.

guest is windows server 2003 32 bit

Re: Extremely Slow Network Speeds On Windows Guests

Posted: 28. Oct 2010, 20:00
by cornbread
any ideas on what would be causing such horrible speeds?

Re: Extremely Slow Network Speeds On Windows Guests

Posted: 28. Oct 2010, 20:23
by Perryg
Actually no I don't. I usually have somewhere around 18MB to 20MB depending on where I am writing the data. I do know that if I write to the same disk that I am using it is lower, but figure that the HD transfer rate is what is causing that since it is reading and writing to the same drive at the same time via the network connection.
I do have better throughput using the Virtio network adapters. They have been ported to Windows but I have not tried them yet.

Re: Extremely Slow Network Speeds On Windows Guests

Posted: 28. Oct 2010, 23:25
by cornbread
Does it matter that i'm using built in network bridge instead of doing it through the host?

I'm really baffled to why this is happening. I can't find info on it anywhere.

Re: Extremely Slow Network Speeds On Windows Guests

Posted: 28. Oct 2010, 23:31
by Perryg
Maybe. Explain exactly what you mean by built-in bridge.

Re: Extremely Slow Network Speeds On Windows Guests

Posted: 30. Oct 2010, 10:01
by cornbread
I mean just going into vbox settings and choosing bridge instead of doing it in ubuntu with another network device like so

Code: Select all

    auto eth0
    iface eth0 inet manual

    auto br0
    iface br0 inet dhcp
    bridge_ports eth0 vbox0

    # The loopback network interface
    auto lo
    iface lo inet loopback

Re: Extremely Slow Network Speeds On Windows Guests

Posted: 30. Oct 2010, 14:56
by Perryg
Ok I see. Yes it can slow things down and by more than just a little. VBox has supported bridged mode direct for some time (router required). It has been a long time but if memory serves my network speed was a lot lower using software bridging. Do you need to software bridge?

Re: Extremely Slow Network Speeds On Windows Guests

Posted: 31. Oct 2010, 05:33
by cornbread
I've been using the setting from inside virtualbox. is that the slower way. or is it slower to do it in the interfaces file?