Configuring Systems for Terminals, Printers, and Other Serial Devices (32022-90057)

Dynamic Configuration and DTS Shutdown/Restart
Dynamic Configuration
Chapter 4
58
NMCONFIG and NMCONFIX Files
Dynamic Configuration uses both files NMCONFIG.PUB.SYS and NMCONFIX.PUB.SYS to
manage the devices created by the DTS subsystem. When users wish to make any
dynamic change, NMMGR will be used to modify the configuration in
NMCONFIG.PUB.SYS. When DTCCNTRL is invoked, either within or from outside of
NMMGR, NMCONFIG will be compared to NMCONFIX and the desired changes will be
made to the system configuration. When the operation has completed successfully, the
changes will be written to NMCONFIX. The configuration in NMCONFIX will always
match the actual configuration of the DTS subsystem.
If any errors are encountered, then information will be saved in the NMCONFIG file
that will allow DTCCNTRL to be re-invoked to complete the changes at a later time. If an
operation is partially successful, then those changes that are successful will be written to
NMCONFIX. For example, if you delete two ldevs and the second ldev can't be deleted
because it is in use, then DTCCNTRL will save information that will allow the second ldev
to be deleted once the device is no longer in use.
CAUTION If ANY other configuration file is copied to NMCONFIG.PUB.SYS or NMCONFIX.PUB.SYS
then dynamic configuration will be disabled until a DTS shutdown and restart is done or
the system is rebooted. This includes other files from the same system or files copied
from other systems.
If there is some operation that fails, and you wish to undo the change, you can use
NMMGR to change the appropriate screens back to what they were and then invoke
DTCCNTRL.
Compressing the Configuration Files
As your configuration grows and changes, you may find it necessary to compress or
expand your configuration file. When you add items in a file, records are added
sequentially from the beginning of the file. If you delete items from a configuration file,
the records are not immediately recovered, so the middle of the file may contain unused
records. These unused records in the middle of the file are not available for reuse. By
compressing the file, you cause all data to be stored in a contiguous block of records at
the beginning of the file. This frees the unused records to be reused.
Compress the files by accessing the Compress screen in NMMGR from the utilities
menu. To recover unused records enter 0 in the Number of Additional Records field and
press the
[Compress File]
function key. If you enter a positive number, the number of free
records will be increased by the number entered. If you enter a negative number, the
number of free records will be decreased by the entered number. The maximum file size
limit is 65,535 records.
NOTE If you compress the NMCONFIG.PUB.SYS file you must also compress the
NMCONFIX.PUB.SYS file. You will be allowed to compress the NMCONFIX.PUB.SYS file, but
will not be allowed to modify any records.
See the Using the Node Management Services Utilities manual for additional
information on how to compress the configuration files.