The difference between choosing mysql 1gb vs 512mb in virtualmin configuration.


When I had to configure virtualmin first time I logged in I was ask a question about mysql. A question I did not understand and it is not clear. A questions where I dont remember the text string…

First I did choose 1gb because I have 2gb RAM and a 25gb hdd. But my RAM usage was quickly swapping and slowing down my server and homepages. I did reinstall and this time I did choose the option: 512mb.

By comparing the /etc/mysql/my.cnf

I here post what different in the setup…

The first settings is with 1gb the second when choosing 512mb

myisam_sort_buffer_size = 64M vs myisam_sort_buffer_size = 8M
query_cache_size = 16M vs query_cache_size = 0
thread_concurrency = 8 vs thread_concurrency = 0
read_buffer_size = 1M vs read_buffer_size = 256K
read_rnd_buffer_size = 4M vs read_rnd_buffer_size = 512K
sort_buffer_size = 1M vs sort_buffer_size = 512K
table_open_cache: 256 vs 64
table_cache = 256 vs table_cache = 64
thread_cache_size = 8 vs thread_cache_size = 0
net_buffer_length = 16K vs net_buffer_length = 8K

This is just meant as a help for others…


Those settings all come from the MySQL conf files distributed with MySQL.

On Ubuntu 12.04, those can be found in “/usr/share/doc/mysql-server-5.5/examples”.

On CentOS 6, those are found in “/usr/share/doc/mysql-server-5.1.61/”.


Im using Debian 6.05 btw :slight_smile: