by Ken Task.
Please provide the top of the output of 'top'
memory and swap
Please install and run MySQLTuner.
Then share relevant info from:
Performance Metrics
in particular: Maximum reached memory usage, Maximum possible memory usage, and if "Overall possible memory usage with other process is compatible with memory available" reports OK
InnoDB Metrics
in particular InnoDB buffer pool / data size
How many moodle sites? How often running cron for each? What does the scheduling for autobackups look like ... for each site?
What is the largest backup file from each of the sites?
I take it that backup preferences are for full course backups ... including users and events.
In auto, how many backup copies are you keeping?
'SoS', Ken