About the Node Image Mapping Service (NIMS)

Overview of NIMS.

The Node Image Mapping Service (NIMS) maps a node to boot attributes, which are used when the node is booted.

The primary NIMS component is the daemon, nimsd. Interactions with nimsd occur either by sending a Hardware Supervisory System (HSS) event or by using the NIMS command line interface (CLI). The HSS Boot Manager daemon communicates with nimsd via HSS events. All other interactions with nimsd take place through the CLI.

The nimsd daemon provides boot attributes to Boot Manager upon request. Boot Manager uses the boot attributes when it boots or reboots nodes. Boot Manager also provides the boot attributes to the xtcli command.

Two conceptual components, nodes and maps, are affected by nimsd. A node represents a physical, bootable node on the XC system. A map is a collection of nodes, typically all the nodes in a partition, or for a non-partitioned system, all the nodes in the entire system.

The NIMS CLI consists of two commands, cnode and cmap. The cnode and cmap commands replace the nimscli command, which was deprecated in CLE 6.0.UP04 and removed in CLE 6.0.UP05. Be sure to change any scripts that reference nimscli. Prior to UP06, when the cmap command was invoked from within any snapshot (either the booted snapshot or a different snapshot), it would set the active NIMS map for the currently booted snapshot. As of UP06, cmap sets the active NIMS map in whatever snapshot cmap is invoked in. If cmap is invoked in the current snapshot, it sets the active NIMS map for the currently running system. If cmap is invoked in a different, non-running snapshot, it sets the active NIMS map for that snapshot. When the SMW is rebooted into that snapshot, then the active map for that snapshot will become the active NIMS map for the running system. For more information, see the cnode and cmap man pages.

A system can have multiple NIMS maps. However, only one map can be active at a time. The reason to have multiple maps is to differentiate the boot attributes. For example, one map may be a test map to allow booting nodes with a test boot image or a test config set.

Tip: Changes made using cnode affect the active map. If testing a new boot image, for example, use cmap to set the active map to the test map before using cnode to assign the test boot image to one or more nodes.