Graphs "No data file" following major update

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…


  • 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

This topic was automatically closed 91 days after the last reply. New replies are no longer allowed.