Overview
Upgrading NMIS to 8.5.6G is extremely simple: all you need to do is follow the guidance of the interactive installation script, which will perform all the necessary steps that are safely automatable. Since version 8.5.6G the installer also takes care of installing both operating system packages and CPAN perl packages that NMIS depends on.
Please note that the installer script does not overwrite your existing models or configuration items for safety reasons, so a (semi-manual) model upgrade procedure needs to be followed for activating the newest models.
For your convenience the installer offers to save a compressed backup snapshot of your NMIS configuration in root's home directory, and a log of the actions that were performed is saved in install.log in the NMIS directory.
RRD Migration
NMIS 8.5.6G recommends an updated and simplified directory structure for your RRD files, which is more robust and easier to deal with from an administrative perspective: all of a node's RRD database files are kept within the directory <nmisdir>/database/nodes/<nodename>. This new recommended structure is controlled by the settings in models/Common-database.nmis, and great care has been taken to make the migration from old to new layout safe and unproblematic.
NMIS 8.5.6G ships with the tool admin/migrate_rrd_locations.pl and the installer will offer to run it for you automatically. This tool takes care of moving any existing RRD files from old to new location, and merges a new Common-database.nmis with the other settings in your existing file (e.g. custom RRD period values). You can run the tool repeatedly; if there is nothing to migrate, then it'll show that and simply exit. There is a simulation mode for only seeing prospective changes without performing them, and the migration tool also creates a rollback script in /tmp which can be used to reverse a (partially or fully completed) RRD migration.
It is highly recommended that you let the installer perform the RRD migration on your behalf.
General Upgrade Procedure
Once you've unpacked the NMIS tarball you will see install.pl in the NMIS source directory. Running ./install.pl -h will show you what options it offers.
A simple invocation of ./install.pl will prompt you for a few bits of necessary information and confirmations, after which the tool will backup your current NMIS installation and then perform the upgrade or installation steps.
Once the installer has finished its work you will likely need to review your config and model files and determine whether there are any customizations that you need to merge with newer files from the NMIS tarball. NMIS live configuration files are in /usr/local/nmis8/conf, the updated material from the release is in /usr/local/nmis8/install; for models please see the page on Upgrading Models.
To simplify the comparison and merging process NMIS provides the helper program admin/diffconfigs.pl. As an example, to check your Config.nmis against the one included with a new NMIS release you would use the tool like this:
cd /usr/local/nmis8
./admin/diffconfigs.pl install/Config.nmis conf/Config.nmis
Comparing install/Config.nmis to conf/Config.nmis
Output format:
"Config Key Path:
- Status in install/Config.nmis
+ Status in conf/Config.nmis"
/system/threshold_period-pkts_hc:
- -15 minutes
+ -5 minutes
...possibly lots more changes...
Difference Summary:
/authentication/auth_user_name_regex
/system/threshold_period-interface
/system/threshold_period-pkts
/system/threshold_period-pkts_hc
The diffconfigs tool now also works for model files.