[GTALUG] MBR and GTP Drives

[Scott Sullivan]

On 07/10/17 08:53 PM, Howard Gibson via talk wrote:
>     From fdisk, I could see that the Western Digital drive was GTP.  The new Seagate drive identified itself as "dos", which means it is MBR.  Best Buy offered me a newer Seagate at a slightly lower price but one is claimed explicity to support Linux, and it supports some older protocols.  When I told the people at the store I wanted MBR, not GTP, they just stared at me.

Partitioning is not a property of the hardware, but of the data written 
to it. Manufactures my preformat a disk with MBR or GPT but your under 
no obligation to use it.

As you've pointed out, you can change it after the fact, but that is a 
destructive operation. MBR and GPT are mutually exclusive. Picking on 
must be done before installation or writing of data you'll want to keep.

I've developed a habit of zeroing the area where the two partition 
tables may live. Then letting my system boot normally, the install will 
offer to partition the disk appropriately for the type of disk, and 
manner in which we booted (UEFI vs MBR).

dd bs=1M count=5 if=/dev/zero of=/dev/sdX
\  \     \       \            \- Your disk.
  \  \     \       \- A special device file that is infinite zeros
   \  \     \ 5 blocks worth from 'if', number is larger then needs to be
    \  \ Copy in block sizes of 1 megabyte
     \ 'Convert and Copy'

-- 
Scott Sullivan