[root@ns1 /]# parted -s /dev/sda print

Model: WDC WD80 0JD-19LSA0 (scsi)
Disk /dev/sda: 80.0GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number  Start   End     Size    File system     Name  Flags
 1      17.4kB  31.5GB  31.5GB  ext4                  raid
 2      31.5GB  32.5GB  1049MB  linux-swap(v1)


[root@ns1 /]# parted -s /dev/sdb print

Model: WDC WD40 0JD-19MSA1 (scsi)
Disk /dev/sdb: 40.0GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number  Start   End     Size    File system     Name  Flags
 1      17.4kB  31.5GB  31.5GB  ext4                  raid
 2      31.5GB  32.5GB  1049MB  linux-swap(v1)


[root@ns1 /]# cat /proc/mdstat

Personalities : [raid1]
md0 : active raid1 sda1[0] sdb1[1]
      30719936 blocks [2/2] [UU]
unused devices: <none>

[root@ns1 /]#