Starting in InnoDB 1.1 with MySQL 5.5, the
asynchronous I/O
capability that has been supported on Windows systems, is now
available on Linux systems. (Other Unix-like systems continue to
use synchronous I/O calls.) This feature improves the scalability
of heavily I/O-bound systems, which typically show many pending
reads/writes in the output of the command SHOW ENGINE
INNODB STATUS\G
.
If a problem with the asynchronous I/O subsystem in the OS
prevents InnoDB from starting, set the option
innodb_use_native_aio=0
in the
configuration file. This new configuration option applies to Linux
systems only, and cannot be changed once the server is running.
For more information about InnoDB I/O performance, see
Section 7.5.7, “Optimizing InnoDB
Disk I/O”.