Linux : wipe a filesystem signature from a device

# wipefs /dev/sdm (this will show the existing filesystem signature)
offset               type
----------------------------------------------------------------
0x438                ext4   [filesystem]
                     UUID:  7a744324-a26b-47fe-9d91-24fee3cc09b4


# wipefs -a /dev/sdm (this will erase the signature)
2 bytes [53 ef] erased at offset 0x438 (ext4)

# wipefs /dev/sdm
#