Re: Speed parameter for 'dd' command

[Pádraig Brady]

On 17/12/09 12:20, sdrb wrote:
> Hello,
>
> I'd like to ask if it would be possible to add new parameter to "dd"
> command. I was thinking about "speed" parameter. Sometimes it is needed
> to use "dd" with very large amount of data and the whole process can
> cause quite high load average for long time.
> Maybe it would be good idea to add some kind of limitation for "dd"
> command - and limits I/O operations to given kB or MB per seconds?
> For example:
>
> dd if=/dev/zero of=/dev/sda speed=4096k
>
> and it will limits I/O operations to 4MB/s?
>
> Of course the whole "dd" process will take more time to complete in this
> case, but at the same time it will be possible to keep load average in
> more acceptable values and thus make using system more comfortable.
>
> What do you think?

Well you would only slow things down so as to not take resources
from other processes, but they in turn might not be constantly
using those resources. I.E. it would be better to tell the
system the priorities and let it sort it out optimally.

Have you tried ionice?

cheers,
Pádraig.