ORA-15037:disk '/dev/asmvg02/rasmdisk02' is smaller than mimimum of 4 MBs

while creating a asm diskgroup I encountered this issue .

SQL> create diskgroup DFDG external redundancy disk

'/dev/asmvg02/rasmdisk02'; 2

create diskgroup DFDG external redundancy disk

*

ERROR at line 1:

ORA-15018: diskgroup cannot be created

ORA-15031: disk specification '/dev/asmvg02/rasmdisk02' matches no disks

ORA-15037: disk '/dev/asmvg02/rasmdisk02' is smaller than mimimum of 4 MBs

asking the SA he verified

vgdisplay -v /dev/asmvg02

diskinfo /dev/rdisk/disk11

and compared with the other working diskgroup disks.

but it didnt give any indication why i was hitting this error for this new diskgroup i am trying to create . So i gave a shot at dd and ifter that i was able to create diskgroup

+ASM:/dev/asmvg02: dd if=/dev/zero of=/dev/asmvg02/rasmdisk02 bs=4096 count=12800

12800+0 records in

12800+0 records out

+ASM:/dev/asmvg02: sqlplus '/as sysasm'

SQL> create diskgroup DFDG external redundancy disk

'/dev/asmvg02/rasmdisk02'; 2

Diskgroup created.