MYSQL 5.5 innodb_use_native_aio will not enable

[jason clifton]

I built mysql 5.5 from source on an Ubuntu linux server distribution with all the defaults. The install went well with no errors, and the server starts and runs well with no errors.

Looking at the output from show variables; I noticed that innodb_use_native_aio was off which I found strange since the default is On.

I added innodb_use_native_aio = 1 to my my.cnf and restarted mysql. The startup log showed no errors but the show variables still show it to be set to off. So I edited the line to innodb_use_native_aio = ON and restarted mysql and I get a warning in the log about the line being invalid - so I know for a fact I am in the right my.cnf file.

What am I missing? Did I need to add something to the build parameters for support for this? Or could there be something else in my configuration causing this?