What I learned about Linux AIO today

• June 10, 2015
• linux  
• aio  

1. There is no filesystem that implements the AIO fsync operation.
2. When performing AIO reads on vboxfs (VirtualBox filesystem) it will return -EPROTO. No idea why that happens.
3. Neither vboxfs nor tmpfs suport O_DIRECT.
4. AIO seems to work as advertised on XFS, with or without O_DIRECT.