Unix disk copy using dd ?

[Dave McGuire]

On May 3, 2007, at 4:23 PM, Doc Shipley wrote:
>>> dd also seems to have some implementation-specifics
>>> baked into it. On Solaris I was completely unable to
>>> transfer a raw VMS disk image from one drive to
>>> another (identical) one using dd; however the same
>>> transfer worked correctly under Linux.
>>   This is not dd, but the disk device drivers underlying OS.
>
>   More specifically, it's the Solaris volume manager, isn't it?  I  
> forget the specific incantation, but it is possible to tell Solaris  
> "Forget about it" and treat a disk as a raw resource.

   Nope, nothing at all to do with the volume manager.  All it does  
is deal with things like automatically mounting filesystems when they  
come up, such as when a CDROM is inserted.

   The issue concerns partitioning and where "data" starts on the  
disk...and most importantly, whether or not that data includes the  
block containing the partition table.  Traditionally, the "c"  
partition on a Unix system means "the whole disk" but unfortunately  
(from what I've seen) that doesn't include the block containing the  
partition table on some systems.

>   It's probably a good thing for most users/workloads, but mostly  
> Sun's volume manager just irritates me.

   Same here.  Edit /etc/vold.conf to make it ignore the stuff you  
want it to.

            -Dave

-- 
Dave McGuire
Port Charlotte, FL