Background
When installing Virtualmin, the system will prompt for small, medium, large and huge. The question is how are these parameters defined? By examining the `feature-mysql.pl` file on the Virtualmin GPL GitHub repository we will see a Perl subroutine list_mysql_size_settings which shows the parameters used. The parameters differ if you’re using myisamchk or the older isamchk.
For example, here are some numbers for myisamchk systems (there are many more!):
- Small
- key_buffer_size = 16K
- sort_buffer_size = 64K
- read_buffer_size = 256K
- read_rnd_buffer_size = 256K
- myisam_sort_buffer_size = [intentionally left blank]
- thread_cache_size = [intentionally left blank]
- Medium
- key_buffer_size = 16M
- sort_buffer_size = 512K
- read_buffer_size = 256K
- read_rnd_buffer_size = 512K
- myisam_sort_buffer_size = 8M
- thread_cache_size = [intentionally left blank]
- Large
- key_buffer_size = 256M
- sort_buffer_size = 1M
- read_buffer_size = 1M
- read_rnd_buffer_size = 4M
- myisam_sort_buffer_size = 64M
- thread_cache_size = 8
- Huge
- key_buffer_size = 384M
- sort_buffer_size = 2M
- read_buffer_size = 2M
- read_rnd_buffer_size = 2M
- myisam_sort_buffer_size = 64M
- thread_cache_size = 8
The point of this article is that if you’re doing MySQL optimization, you need to take some parameters into consideration. This should be a good starting point.