slow down dd - how?

[Thomas]

On Thu, Jul 08, 2010 at 05:50:52PM +0200, Jozsi Avadkan wrote:

Hi,

> How can I slow down dd?
> 
> I don't want to slow down the pc, when generating a big file [~40
> GByte].
> 
> Does ionice work properly?
> 
> Thank you for any help! :\

you could use some creative shellscripting (probably in addition to idprio):

dd if=/dev/zero bs=1024k | ( dd bs=1024k count=10; sleep 3 ) | dd bs=1024k of=/dev/somewhere

This pauses for 3 seconds for every 10MB written. Try some variations of
bs, count and sleep, until you find an acceptable compromise between speed and
imposed load.

Regards
Thomas