On this page I collect tips & tricks on how to optimize your system for running MySQL. Some tips are in general usefull for optimizing your system.
Older Linux systems (at least 2.6.16) need 'irqbalance' when the system is SMP (multicore - NOT hyperthreading)
Every time MySQL reads or writes from a table, the kernel updates the inode: it stores the last access time. this can have a negative impact. at "noatime" to your fstab to let it stop doing this. use "mount -o remount,noatime /var/lib/mysql" (when you have a seperate filesystem mounted on /var/lib/mysql, of course) to set this at runtime. kernel 2.6.20 has "relative atime" which reduces the need for noatime
Put your databases on disks seperate from the other installed software
Put your database on a RAID-1 diskset
If you have > 20% write access, do NOT put the databases on RAID-5!
When you do frequent update/delete queries, you might want to run this script 'optimize_mysql.tar.gz' (from cron for example) when the system is idle-ish
Choosing filesystem: this page. Conclusion is more or less (read the page!) use ext3 with data=writeback - make sure your system is on a UPS though
When using InnoDB tables, set "set-variable = innodb_buffer_pool_size=256M" in my.cnf where 256M should be 70% of your free memory (aprox) - as innodb doesn't use mysql's own buffers
Use the 'cfq' IO scheduler: "echo cfq > /sys/block/hda/queue/scheduler"
Disable the binary log if not needed.
mount the filesystem on which the database datafiles are located with 'noatime' or 'relatime' (noatime is preferred)