Network Transfer Speed Varies

[CJ145]

Hey I am having a problem when I transfer files across my network. The transfer speed will vary alot.

Ex:

It is from a windows xp SP1 box to a gentoo box via ftp, but it also happens with windows file sharing. It's a wired network to my Dlink DI-614+ through good cat5e cables.

 

[Smokeys]

What kind of files are you transfering? one large file? multiple large files? a mix? how many?

 

[su root]

If possible, bench them both against a 3rd computer, that will tell you which one is causing the problem.

 

[CJ145]

I was tranfering large files as I know that small files will slow inbetween each one. I don't have a 2nd box to bench against because it is on wireless in another room. (11mbit)

Edit: update: I noticed some more things today. When sending something to my server it will do what is pictured above (jump from like 80mbit to 1mbit) but when I am receiving from it it's a steady 30mbit/s. I have tried 2 different nics in my server. I wonder if it's the hdd.

 

[su root]

What's the output of
hdparm /dev/hda
(or whatever your harddrive is)
and the output of:
hdparm -tT /dev/hda
(that will run some speed tests..)

Right now I'm guessing that your problem is a harddrive write speed issue

 

[CJ145]

root@server cj # /sbin/hdparm /dev/hdb

/dev/hdb:
multcount = 16 (on)
IO_support = 0 (default 16-bit)
unmaskirq = 0 (off)
using_dma = 0 (off)
keepsettings = 0 (off)
readonly = 0 (off)
readahead = 256 (on)
geometry = 65535/16/63, sectors = 117231408, start = 0

root@server cj # /sbin/hdparm -tT /dev/hdb

/dev/hdb:
Timing buffer-cache reads: 1656 MB in 2.00 seconds = 826.47 MB/sec
Timing buffered disk reads: 16 MB in 3.24 seconds = 4.93 MB/sec

 

[su root]

Try this:
hdparm -d 1 -A 1 -m 16 -u 1 -a 64 /dev/hdb

That turns on DMA, and a bunch of other settings that should speed up your harddrive. With DMA not on, your system would be using PIO to communicate with the drive, taking oodles and oodles of CPU time, and generally going very slow.

Bench it after running those commands, and see if it improves performance with network writes. If you like it, run this command to keep the config:
hdparm -k 1 /dev/hdb

 

[CJ145]

it won't let me turn DMA on.. it's giving me an operation not premitted.

 

[Smokeys]

Then you didn't build DMA support in your kernel

 

[su root]

Yup, you didn't select the right motherboard chipset support to compile into your kernel.

I recently ran into the same problem here