dd optimizing via netcat?

Linux_Kidd · 01-02-2007, 06:06 PM

i tried to do dd over netcat via knoppix 5.1

2 t60 laptops with 60GB sata drives. 10/100 ethernet to a 10/100 switch (next time i'll use a x-over cable)

destination was netcat -l -p 10000 |dd of=/dev/sda
source was dd if=/dev/sda |nc 192.168.1.2 10000

taking a very very long time to dd the disk (took 1.89hours @ 8.8MB/s). is there a way to optimize block size to coincide with ethernet MTU ?? is bs=1024k the best size to use?

i know this is probably old hat for most... but thanks for any info.

theNbomr · 01-03-2007, 11:04 AM

That doesn't sound completely out of whack to me. 8.8MB/s is about 75 megaBITs per second, which is somewhere near saturation of a 100Mbit ethernet.

--- rod.

Linux_Kidd · 01-03-2007, 12:08 PM

Quote:

Originally Posted by theNbomr

That doesn't sound completely out of whack to me. 8.8MB/s is about 75 megaBITs per second, which is somewhere near saturation of a 100Mbit ethernet.

--- rod.

saturation is not the issue, its the IP overhead that i'm trying to reduce, thereby making the copy faster.

8.8MB = 70.4Mb = ~70% of fast-E, not quite near saturation.

i'm doing another copy now with bs=1024k, will post those results later.

thanks