This question is similar to set open_files_limit, but there was no good answer.

I need to increase my table_open_cache, but first I need to increase the open_files_limit. I set the option in /etc/mysql/my.cnf:

open-files-limit = 8192

This worked fine in my previous install (Ubuntu 8.04), but now in Ubuntu 10.04, when I start the server up, open_files_limit is reported to be 1710. That seems like a pretty random number for the limit to be clipped to.

Anyway, I tried getting around it by adding a line like this in /etc/security/limits.conf:

mysql   hard   nofile   8192

I also tried adding this to the pre-start script in mysql's upstart config (/etc/init/mysql.conf):

ulimit -n 8192

Obviously neither of those things worked. So where is the hoop that has been added between Ubuntu 8.04 and 10.04 through which I must jump in order to actually increase the open files limit?