Network or Samba slow, except when running iftop?
 

Hi there,

I'm running Ubuntu 6.06 LTS (AMD64) on one of my servers (other servers run Ubuntu too btw). This server is equipped with an onboard NIC based on the Realtek 8169 chip. Using the stock kernel driver, the interface seems to work fine. However, when transferring files from a Windows workstation (using a Samba share)I don't get speeds over 0,5Mb/sec. However, as soon as I start iftop, the speed goes up to about 10MB/sec, which is fairly normal / good for a 100Mbit LAN. Stopping iftop makes the speed go down again.

Any clues why this is happening? When using SCP for file transferring, speeds are just good. Is this a hardware issue? Or a (known) issue with Samba?

All my software is of the latest available versions.

Thanks.

If I understand you right, you are doing SAMBA --> Windows.

Look up socket options for SAMBA.

If want near 1 Gb speeds (about 133 MB per second), you will need at least four hard drives in RAID-0 (striping). The four hard drives compensates for the minimum speed for IDE or SATA hard drives and filesysmtem overhead. Use XFS or JFS as the filesystem with custom format options.

On my desktop computers, I get around 11 MB per second (SAMBA --> Windows or SAMBA --> SAMBA) with out any help from another program and with out using RAID-0, but just a single hard drive. My notebook computer has a limit of about 4 MB (hardware limitation), so changing my settings on computers using SAMBA will not work for me on that type of computer. My network is 100 Mb and one of my computers uses a NIC that has a Realtek 8169 (32-bit).

The Realtek 8169 NIC chip can not handle real 1 Gb speeds in full duplex mode because it is on a 32-bit bus going at 33 MHz. When it is set in half duplex mode, it could handle 1 Gb speeds.

b = bits
B = bytes

Wow! What gives, I have the same problem - Ubuntu 6.06 LTS on a P4 ~2.2Ghz, using a Realtek based Gb card. I get the same .5Mb/s transfer over Samba and using an iScsi endpoint. Once iftop starts, receive rate immediately goes to ~20-22MB/s. Maybe some hardware issue with Realtek. I'm going to try to go back to the 100Mb onboard intel chip and see what happens...

One further note - upgrading to the latest Realtek driver made no difference...

You have a software problem.

I have a Realtek 8169 NIC and it is in a Pentium 4 2GHz (Northwood core). The NIC have to go through two PCI bridges because it is on a combo card from Koutech. I get the maximum throughput that my network allows which is 100 Mb. Though I use Gentoo.