So I’ve got this database, this large database, on a large box with 24G of memory.

I’m using SLES 11.1 with MySQL 5.5 Percona XtraDB configured to use an innodb_buffer_pool of 14G.

My theoretical max memory footprint should be about 16.4 GB.

[OK] Maximum possible memory usage: 16.4G (69% of installed RAM)

My tables are partitioned daily, and split into single files. As the day goes on, I watch mysql slowly eat all the systems memory until it finally restarts itself.

For example…

PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
 8371 mysql     10 -10 18.1g  16g 6576 S  136 68.9 254:03.69 mysqld

Why is the virtual size 18.1g? I have no idea.

If I run FLUSH TABLES in mysql, this will free up. Does anyone know why?