[root@localhost /]# fdisk /dev/sd sda sda1 sda2 sda3 sdb sdb1 [root@localhost /]# fdisk /dev/sdb Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel Building a new DOS disklabel with disk identifier 0x34c1337c. Changes will remain in memory only, until you decide to write them. After that, of course, the previous content won't be recoverable. Warning: invalid flag ..