This topic discusses the purpose of tape and optical devices in i5/OS® logical partitions and the placement rules that you must follow when installing these devices.
A removable media device reads and writes to media (tape, CD-ROM, or DVD). Every i5/OS logical partition must have either a tape or an optical device (CD-ROM or DVD) available to use. The server uses the tape or optical devices as the alternate restart device and alternate installation device. The media in the device is what the system uses to start from when you perform a D-mode initial program load (IPL). The alternate restart device loads the Licensed Internal Code contained on the removable media instead of the code on the load source disk unit. It can also be used to install the system.
Depending on your hardware setup, you might decide that your logical partitions will share these devices. If you decide to share these devices, remember that only one logical partition can use the device at any time. To switch devices between logical partitions, you must move the IOP controlling the shared device to the desired logical partition.
For more information about the placement rules for alternate restart devices, see Alternate restart device placement rules for i5/OS logical partitions.