Background and repro steps:
- Ubuntu 18
- Long overdue update from 1.69 to 21.9 (held back silently because of PHP 7.2 no longer supported).
- Forced upgrade of MariaDB from 10.1 to 10.2 as part of this.
- Testing the update process on a clone of the prod OS, which means the poller doesn’t have access to any of the devices (due to ACL/firewalling restrictions). Hence the poller is not producing any new data, which is as expected.
- Apart from this, we are checking the general health of the cloned OS post upgrade to validate the upgrade steps before applying the same to the prod instance.
- Everything generally looks fine, except…
Problem/question:
- Certain graphs show “No data file mempool-fortigate-system-0.rrd” (obviously this is the memory graph set for some FortiGate devices).
- In the /opt/librenms/rrd directory we see a single file “mempool-fortigate-0.rrd” (last updated before the upgrade procedure). That obviously isn’t the same name as the UI/PHP is looking for (missing “system-”).
- We don’t want to lose RRD graph history as part of this update.
- We believe that RRD graph data is extracted from the DB, perhaps by the poller, and the files are generated/updated dynamically, for all available history, from the DB data, but we are not sure enough about this to know whether we are going to have a problem when applying this upgrade procedure to prod. Since the poller isn’t healthy on this cloned instance we can’t be sure.
- So the question is whether we can safely ignore this issue (ie it won’t happen if we follow the same procedure on prod, assuming the poller is running fine)?
validate.php output
====================================
Component | Version
--------- | -------
LibreNMS | 21.9.0-8-g0d499b538
DB Schema | 2021_25_01_0129_isis_adjacencies_nullable (217)
PHP | 7.4.23
Python | 3.6.9
MySQL | 10.2.40-MariaDB-1:10.2.40+maria~bionic
RRDTool | 1.7.0
SNMP | NET-SNMP 5.7.3
====================================
[OK] Composer Version: 2.1.8
[OK] Dependencies up-to-date.
[OK] Database connection successful
[OK] Database schema correct