Overview
This article provides steps on how to troubleshoot and solve issues resulting in an error that appears when manually creating a backup file from the Maintenance section of UniFi Network. Some of the steps in this article can also help solve issues such as the auto-backup files not being created at the time they are scheduled.
Table of Contents
Introduction
The error produced when it can't create a backup file can vary depending on the observed location of logging. See examples below:
Web UI
Server.log
[2018-11-27 12:02:11,709] <backup> ERROR system - Fail to create a backup for version '5.9.29' [2018-11-27 12:02:11,709] <backup> ERROR system - Info on backup error is...
Java logging between events omitted.
[2018-11-27 12:02:11,709] <backup> INFO system - [server backup][BACKUP] end
[2018-11-27 12:02:11,711] <backup> INFO event - [event] Backup failed
The logging in the web UI will not show up for auto-backup, only when manually attempting and failing to create a backup.
Troubleshooting Steps
1. Try a different browser.
Before progressing to the steps below, try using a different browser to see if the problem resides with the browser or with the UniFi OS Console (or other UniFi Network application host). Chrome is Ubiquiti's preferred browser.
It can also be useful to use the developer console found on most modern browsers. This console can be found under Developer Tools (Ctrl + Shift + J on Windows or Linux/Cmd + Opt + J on macOS).
2. Does the problem occur when using webRTC, direct connection, or both?
There are three options available when launching the UniFi OS Console from the UniFi Remote Access Dashboard. After clicking on a UniFi OS Console in the main list, the Sites Overview panel will pop out with the different possibilities. When selecting the "Launch using Cloud" option, WebRTC is used. When selecting hostname or IP of UniFi OS Console, a direct connection is used. Try creating the backup on both types of connections if possible. If the issue is persistent on both, move on to the next step.
3. Check Server.log logging.
To see the logs that are printed to the server.log file, download them within Settings > System Settings > Maintenance > Support Information. As mentioned above, if the backup is failing this will provide the most information as to why the backup is failing.
Debug Logging for server.log
Navigate to Settings > Maintenance > Services to adjust the system logging level if more output is needed to diagnose the issue.
4. Database Corruption
In most cases, this will be the issue that prevents the application from creating a backup. Database corruption will cause MongoDB to deliver errors when trying to read corrupt or invalid entries.
For more instructions on how to repair a database see our article here.
5. Invalid Permissions
Invalid permissions on user created files can cause issues when trying to back up as well. The most common user created file is the config.gateway.json. Check this file to ensure it has proper permissions. It should be an owner and a group of unifi:unifi for Linux/Cloud Key users. Find more information about the config.gateway.json file here: UniFi - USG Advanced Configuration
6. Verify that you are using a supported Java version
If your UniFi Network application is a software install and not running on a UniFi OS Console, make sure that your system is running a supported version of Java which will be noted in the Release Notes. For current versions, an updated version of Java 8 must be installed on the system hosting the UniFi Network application. Java 9 and later are not supported.
Related Articles
UniFi - How to Remove (Prune) Older Data and Adjust Mongo Database Size
UniFi - Repairing Database Issues on the UniFi Network Application