I have tape drive in one Lpar. when i saw that time tape is in defined state. After that i deleted the tape drive using the rmdev -R command. Then fired the cfgmgr -v command. But I am not getting the tape drive. Now the drive is even not in defined state also. It is not shown the tape drive. How will i check the tape drive is availaple are not.
Thanks in advance.
Only devices in state "Available" are usable. A device in state "Defined" means that once there was such a device but has been removed/inactivated since and only the devices information is still left.
Exactlxy this definition you have removed by issuing rmdev. (Btw. consider using the "-d" switch to rmdev.) When you ran cfgmgr again the device was not created because it has still not been there and therefor the config manager had no reason to create the device entries (in the ODM). But the device was not attached to the machine (or simply switched off) before either because otherwise the devices status wouldn't have been "Defined".
To answer your question: you can immediately tell that the device is unusable, because if it would be usable it would at least be in state "Available".
I hope this helps.
bakunin