Unlike other network adapters, ATM adapters cannot be used to boot a machine. This means that installing a machine over an ATM network requires special processing.
Normally when a machine performs a network boot over a specified adapter, the adapter is configured by IPL-ROM or firmware. Then a boot image is transferred from the boot server to the client using tftp. This boot image performs further configuration and mounts network installation resources before starting the BOS installation.
Since an ATM adapter cannot be configured by IPL-ROM or firmware, a boot image cannot be obtained over the network to perform a BOS installation. This means that the NIM bos_inst operation must copy a boot image to the hard disk of the client before the machine is rebooted. Some ODM information is also saved on the client machine so that when the machine is rebooted, the ATM adapter can be configured properly.
NIM clients may not have the executables installed to support the special processing required for installation over ATM, so the directories /usr/lib/boot/bin and /usr/lpp/bos.sysmgt/nim/methods are mounted at the client from the NIM master. These directories contain executables that are run during the setup performed by the NIM bos_inst operation.
After the initial setup completes, an "at" job is issued to reboot the machine after one minute has elapsed. When the machine reboots, the boot image that was copied to the hard disk configures the ATM adapter and mounts network installation resources for the BOS installation. The installation then proceeds as normal until the customization phase. During NIM customization, the ATM adapter is not reconfigured with a mktcpip command since the ODM already contains information carried over from before the machine was reinstalled. All other aspects of NIM customization are the same as for non-ATM clients.
Note: Configured NIM clients have the bos.sysmgt.nim.client fileset installed, are registered in the NIM master database, and have a valid /etc/niminfo file.
Prior to the support of BOS installations over ATM, it was necessary to define ATM networks as "generic" networks for performing other types of NIM operations. To convert generic networks into ATM networks, enter the following command:
nim -o change -a new_type=atm (network)
The adapter names for the client interfaces on the ATM network will automatically be set to at0 in the NIM database.
If desired, the name of the network can be changed also:
nim -o change -a new_name=(new network name) (current network name)
Since BOS installation over ATM requires a special boot image to be written to the hard disk of the client, the original boot image on the machine will be lost. This means that if the installation is aborted or fails before BOS is reinstalled, it will not be possible to perform a normal reboot of the client unless system maintenance is performed. By performing system maintenance, a new boot image can be created on the hard disk to allow the machine to be booted for normal use. The following procedure should be used:
If errors are detected during the NIM bos_inst operation and the client machines hasn't rebooted, it is possible to stop the machine from rebooting, and then execute the sequence of commands in the above step 4 on the running system. To stop the reboot, use the following procedure:
The first name in the output field will be the name of the job.
Example: $ at -1 root.884205595.a Wed Jan 7 14:39:55 1998 $ at -r root.884205595.a at file: root.884205595.a deleted
Note: The reboot can also be prevented by removing the shutdown script that the "at" job was instructed to run by entering: rm/tmp/_NIM_shutdown