[CentOS] how can I tell what's on the MBR of /dev/sda?

Fri Apr 10 01:34:17 UTC 2015
John R Pierce <pierce at hogranch.com>

On 4/9/2015 5:22 PM, Chuck Campbell wrote:
> Subject says it.
>
> I would like to find out if I have anything written on the MBR of a 
> disk in my system /dev/sda, or any other device.
> If there is something there, is it readable, or recognizable to humans?

the MBR contains both binary boot code, which is not human readable, and 
the master partiion table for the device. you can display the latter like...

$ sudo parted /dev/sda print
Model: ATA Crucial_CT512M55 (scsi)
Disk /dev/sda: 512GB
Sector size (logical/physical): 512B/4096B
Partition Table: msdos

Number  Start   End    Size   Type     File system  Flags
  1      1049kB  525MB  524MB  primary  ext4         boot
  2      525MB   512GB  512GB  primary               lvm


note tho, that if "Partition Table" instead says gpt, then the disk is 
formatted GPT and doesn't use the MBR.

$ sudo parted /dev/sdb print
Model: ATA ST32000644NS (scsi)
Disk /dev/sdb: 2000GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number  Start   End     Size    File system  Name  Flags
  1      65.5kB  2000GB  2000GB               pri   raid


-- 
john r pierce, recycling bits in santa cruz