I'm running a large query, and I'm getting the following error:
_mysql_exceptions.InternalError: (3, "Error writing file '/tmp/MYo8b3Z4' (Errcode: 28)")
This means I'm running out of disk space in my tmpdir which is evidently /tmp. Now, I want to make sure that this is indeed the problem. So I run the query, and constantly monitor the contents of /tmp. But as the query is executing, the contents of /tmp do not change at all. No new files, no existing files changing size.
What does this mean? Is my tmpdir somewhere else?
( I do have a line in my.cnf that reads tmpdir = /tmp
)