Robert P. J. Day wrote:
On Fri, 31 Aug 2007, Ian Malone wrote:
> Karl Larsen wrote:
>> Jacques B. wrote:
>>> Because the clone would be of a
>>> running system. So booting from it would be comparable to booting
>>> from a system that crashed (I'm making an educated guess at that one).
>>>
>> Not a good guess. To use DD you need a computer with dd and a fast cpu. I
>> did top while dd was working and it was taking 70% of the cpu's time :-P
>>
> It's one of the oldest Unix programs: it will copy as fast as your
> system can go. Yes, a fast system will copy faster.
i'm guessing he failed to provide a decent blocksize so dd was using
the default blocksize of 512 bytes. that will slow things down in a
hurry.
How would you go about estimating a decent blocksize (other than by
testing)? My first instinct would be to go for some percentage of
the drive's cache. (And it had better be a factor of the amount you
want to copy I suppose.)
--
imalone