Werk #7444: Rename metric name in Filesystem checks from mount point to fs_used

Filesystem Nagios check plug-in stored the filesystem usage of every mount points in the RRD databases under the path of each mount point. Checkmk assigned to every mount point a service, still it kept naming the filesystem usage with the mount point path for compatibility. Our graphing system learned to deal with this unpractical convention, however new features in Checkmk performing bulk access to data can't.

• All sites created with Checkmk 1.6.0 onward will automatically use the new naming convention and don't need to be migrated
• The migration is not mandatory, your Checkmk instance will continue working under the legacy mode until you migrate.
• If you use CRE, you don't need to do the migration
• If you don't plan to do bulk access to data as required by the Historic Data Views for filesystems (see Werk #7445), you don't need to migrate your RRD databases.
• If you want to use the Historic Data Views for Capacity Management on Filesystems, you need to do migration.

The incorporation of Historic Data Views, for Capacity Management, requires querying the filesystem usage of all host in a given time window. It becomes prohibitive expensive to do such request since first every service is queried for its mount point name and then every RRD is individually queried again for the mount point name data.

In this werk we provide a migration script that would edit all meta data files describing the RRDs that receive output from all our supported filesystem checks. It will also set a flag in your config so that Filesystem check plug-ins start delivering usage performance data under the static name of fs_used.

You are advised to do a backup of your RRD files and journal files before performing the migration and your Checkmk instance needs to be stopped during the migration.

Migration is one way and needs to be performed once per site any rollback has to be done from your own backup.

Instructions:

1. Stop your omd site. (# omd stop SITE)
2. Do a full backup of your site (# omd backup SITE)
3. Log in as the site user ($ sudo su - SITE)
4. As site user run the script ($ bin/update_rrd_fs_names.py). You can optionally use -n for a dry-run.
5. Start the site again.

To the list of all Werks