Known problems and limitations

This section contains information on:

• ``Limitations''

• ``Adding and deleting components''

• ``Shared memory segments''

Limitations

This version of DMI-SP supports only DMI 2.0. It does not support:

• DMI 1.x and the data block interface. Only the DMI 2.0 procedural interface is supported.

• DMI 2.0s (secure DMI).

• Unicode. All MIFs are taken to be in the ISO 8859-1 alphabet.

• Runtime overlay programs. These are component instrumentation programs run by the Service Provider to retrieve or set the value of an attribute at the time that the action is requested by a management application. This version of the DMI-SP supports only direct interface programs; that is, instrumentation programs which are always running and registered with the Service Provider.

Adding and deleting components

Any user can add or delete components to or from the MIF database, using the rma2 command. You do not need to be logged on as root to do this.

Deleting, then re-adding a component to the MIF database does not cause the component to have the same component ID assigned. Component IDs do not get re-assigned. When components are removed from the MIF database, the MIF database does not shrink in size. Consequently the MIF database continues to grow in size as MIF files are added.

If you need to shrink the MIF database, you may do so manually by performing the following procedure as root:

1. Stop the DMI service Provider by entering:
   
   dmi stop

2. Restart the Service Provider using the recreate database option:
   
   dmi start -r

Shared memory segments

The default UnixWare operating system configuration should allow at least 12 simultaneous DMI client sessions. If you want more than 12 clients, you should read the following information and adjust SHMMNI and SHMSEG according to the formula.

The following kernel tunables are affected by DMI:

SHMMNI

maximum number of shared memory IDs (system wide)

SHMSEG

maximum number of attached shared memory segments per process

The DMI Service Provider itself creates three shared memory segments for internal use; each component instrumentation creates one shared memory segment, and each management application creates one shared memory segment. Therefore the total number of shared memory segments used by DMI applications can be calculated using the formula:

Total used by DMI = 3 + NCI + NMA

where NCI is the number of component instrumentations and NMA is the number of management applications.

The maximum number of simultaneous ``clients'' on the host is equal to the sum of NMA and NCI.