VIRTUALBOX MAC OS X aio_queue_async_request FIX

aio_queue_async_request FIX

Mac OS X kernel configuration

sudo sysctl -w  kern.aiomax=512 kern.aioprocmax=128 kern.aiothreads=16

then restart VirtualBox. These settings will apply until you reboot. To make the changes permanent, add/update the following lines in  

/etc/sysctl.conf:

kern.aiomax=512

kern.aioprocmax=128

kern.aiothreads=16

Note: you can probably set those limits even higher, as

documentation for Sybase

Enabling Host I/O caching for controllers that have local and file-based disks attached seems to have fixed 99% of the issues described above.

The following line enables the Host I/O cache:

VBoxManage storagectl --name --hostiocache on

In my case it was:

VBoxManage storagectl pintail --name SATA --hostiocache on

This probably also makes all the kern.aio* settings irrelevant.

Further implications of enabling the Host I/O cache are described here:

 http://www.virtualbox.org/manual/ch05.html#iocaching