When removing a device on AIX, you may run into a message saying that a child device is not in a correct state. For example:

# rmdev -dl fcs3
Method error (/usr/lib/methods/ucfgcommo):
0514-029 Cannot perform the requested function because a
child device of the specified device is not in a correct state.

To determine what the child devices are, use the -p option of the lsdev command. From the man page of the lsdev command:

-p Parent
     Specifies the device logical name from the Customized Devices
     object class for the parent of devices to be displayed. The 
     -p Parent flag can be used to show the child devices of the 
     given Parent. The Parent argument to the -p flag may contain
     the same wildcard charcters that can be used with the odmget 
     command. This flag cannot be used with the -P flag.

For example:

# lsdev -p fcs3          
fcnet3 Defined   07-01-01 Fibre Channel Network Protocol Device
fscsi3 Available 07-01-02 FC SCSI I/O Controller Protocol Device

To remove the device, and all child devices, use the -R option. From the man page for the rmdev command:

-R
     Unconfigures the device and its children.
     When used with the -d or -S flags, the 
     children are undefined or stopped, respectively.

The command to remove adapter fcs3 and all child devices, will be:

# rmdev -Rdl fcs3