slow down dd - how?

Thomas fwd at
Fri Jul 9 00:32:44 UTC 2010

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


> 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.


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