[linux-lvm] pvcreate is successful but can't vgcreate

[蔡滢]

i want to use LVM to manage my SATA disks attached on arm system and:

pvcreate /dev/sda
Physical volume "/dev/sda" successfully created

vgcreate group1 /dev/sda
No physical volume label read from /dev/sda
/dev/sda not identified as an existing physical volume
Unable to add physical volume '/dev/sda' to volume group 'group1'.

what's wrong and why?