Question:

I am getting MySQL errors from my Deskpro On-Premise install very few minutes. They say that 'an exception occurred while executing' various queries. After the query is the line:

SQLSTATE[HY000]: General error: 3 Error writing file X (Errcode: 28)

or

SQLSTATE[HY000]: General error: 1030 Got error -1 from storage engine

where X is a temporary file of some kind. What is causing this?

Answer:

This means MySQL is running out of disk space when it tries to write a temporary file.

Increase the disk space available to MySQL. Even if it appears that there is still space available on the disk, it's best to leave a minimum of 10GB free.