When a SPOT resource is created, network boot images are created in the /tftpboot directory to support certain NIM operations. Before AIX 4.3, the default behavior of NIM was to create a network boot image for every type of machine and network for which support was available in the SPOT. This resulted in the creation of many unneeded boot images that used a large amount of disk space and slowed down the SPOT creation and check operations.
In AIX 4.3 and later, by default, NIM only creates network boot images to support clients and networks that are defined. If a new client is defined and there is no network boot image already created for it in the environment, then the boot image will not be created until either the SPOT is allocated to the client or a check operation is performed on the SPOT to rebuild the boot images.
When clients are removed from the NIM environment, boot images are not automatically removed. To remove boot images that are no longer necessary for a NIM environment, the list of required machine-network combinations in the environment must be rebuilt. The boot images must then be rebuilt for each SPOT.
To limit or enable boot image creation according to whether the interface is defined from the Web-based System Manager application:
Manage the creation of boot images from the SMIT interface by typing the SMIT fast path:
smit nim_control_boot
To rebuild the list of machine types and networks that must be supported by network boot images in the NIM environment, perform a change operation on the NIM master with the if_discover=yes attribute:
nim -o change -a if_discover=yes master
To rebuild network boot images from a SPOT, perform a check operation on the SPOT with the force option:
nim -Fo check spot name
If an administrator prefers to have NIM always create all possible boot images from the SPOT resources, the if_prebuild=yes attribute can be specified on the master:
nim -o change -a if_prebuild=yes master
To return NIM to the behavior of creating only the boot images that are required for the environment, remove the if_prebuild attribute from the master by setting it to "no":
nim -o change -a if_prebuild=no master