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Ray Morris wrote:
>> Oops, my eyes missed the pipe and second dd when I made my previous
>> comments.  That is pretty good for different disks then yes... not
>> so good for same physical disk.
> 
>    Indeed my tests were done copying from the "old" disk
> to the "new" disk, as the OP is doing, I believe.
> 
>> I actually have some old hacked up dd code I made once to use 16
>> concurrent aio requests with O_DIRECT.  I need to clean it up a
>> bit but it showed great promise.
> 
>    Considering how often "dd" is used for copying large amounts
> of data, even a modest improvement could save many thousands of
> hours of admin time.  I would like to encourage you to do any
> needed cleanup and make it available, preferably integrated with
> GNU dd - it could save hundreds of thousands of dollars worth of
> time.
> -- 
> Ray Morris
> support@bettercgi.com

Thanks to all for the suggestions. I believe I will go the dd route. 
That seems like the best (simplest) option.

Thanks,
Mike