fastest raw device copy?

[Christoph Kukulies]

Christoph Kukulies schrieb:
> Ivan Voras schrieb:
>> Jeremy Chadwick wrote:
>>  
>>> On Fri, Oct 31, 2008 at 09:48:16AM +0100, Christoph Kukulies wrote:
>>>     
>>
>>  
>>>> What would be the fastest way to do that sector by sector copy? 
>>>> I'm  using dd right now,
>>>>
>>>> dd if=/dev/ad0 of=/dev/da0 bs=10000000
>>>>       
>>
>>  
>>> On the flip side, your blocksize (bs) there is quite high for no good
>>> reason.  I'd pick something more like bs=64k or bs=128k.  The default
>>> (512) is too small for what you want, but 10MBytes is silly.
>>>     
>>
>> Not only that, but "10000000" isn't even correct - it needs to be a
>> multiple of sector size. Generally, using suffixes will do the right 
>> thing:
>>
>> dd if=/dev/ad0 of=/dev/da0 bs=1m
>>
>>   
> OK, I understand that 10000000 isn't good, I just thought it wouldn't 
> harm. But if it is a transfer rate killer then I'd better think of 
> typing ^C now. The command is running for 6 hours now.
>
> An idea how I can check the current amount of transfered byed 
> alongside the running dd command? Or watch the current i/o rate?
Ack, I mean "bytes" :)