All entities and resources managed by a NIM master must first be created as NIM objects. Each NIM object belongs to a class of NIM objects (e.g., machines, resources, networks) and has a type. Furthermore, each NIM object has a unique name assigned by the administrator, as well as a set of attributes and operations that can be performed on the NIM object, depending on the type of NIM object. The possible attributes, operations, and other properties are fixed and cannot be changed by the administrator. Predefined and non-modifiable NIM information is stored in the ODM nim_pdattr:

aixnim # odmshow nim_pdattr
class nim_pdattr {
        short class;                                 /* offset: 0xc ( 12) */
        vchar subclass[2048];                        /* offset: 0x10 ( 16) */
        vchar type[2048];                            /* offset: 0x14 ( 20) */
        short attr;                                  /* offset: 0x18 ( 24) */
        vchar name[40];                              /* offset: 0x1c ( 28) */
        long mask;                                   /* offset: 0x20 ( 32) */
        vchar value[2048];                           /* offset: 0x24 ( 36) */
        short h_num;                                 /* offset: 0x28 ( 40) */
        short verbose_num;                           /* offset: 0x2a ( 42) */
        };
/*
        descriptors:    9
        structure size: 0x2c (44) bytes
        data offset:    0x2f8
        population:     623 objects (623 active, 0 deleted)
*/

aixnim # 

Custom NIM objects created by the administrator are stored in the nim_object ODM, with the attributes of these NIM objects stored in another ODM (nim_attr). As long as NIM has not yet been initialized on a NIM master, these two ODMs are empty.

The predefined NIM information is additionally organized into a number of subclasses, but these essentially only have an internal meaning for NIM.

Although all NIM objects and NIM information are stored in ODMs, ODM commands such as odmshow, odmget, or odmchange are not the preferred commands for NIM administration. Besides SMIT, the two most important commands for administering NIM objects are the lsnim and nim commands. The lsnim command can be used to display any information about NIM objects and NIM information. The nim command allows you to perform operations on NIM objects and will be discussed in more detail later.