---
name: "aio"
section: "4"
platform: "linux"
package: "freebsd-manpages"
version: "6.0-5"
release: "Debian 4.0 (Etch)"
platforms: ["linux", "freebsd", "macos"]
url: "https://carta.tech/man/aio/4"
---

# aio(4)

asynchronous I/O

## NAME

**aio** – asynchronous I/O

## SYNOPSIS

To link into the kernel: **options VFS\_AIO**

To load as a kernel loadable module:

```
kldload aio
```

## DESCRIPTION

The **aio** facility provides system calls for asynchronous I/O. It is available both as a kernel option for static inclusion and as a dynamic kernel module.

## SEE ALSO

[aio\_cancel(2)](/man/aio_cancel/2.md), [aio\_error(2)](/man/aio_error/2.md), [aio\_read(2)](/man/aio_read/2.md), [aio\_return(2)](/man/aio_return/2.md), [aio\_suspend(2)](/man/aio_suspend/2.md), [aio\_waitcomplete(2)](/man/aio_waitcomplete/2.md), [aio\_write(2)](/man/aio_write/2.md), [lio\_listio(2)](/man/lio_listio/2.md), [config(8)](/man/config/8.md), [kldload(8)](/man/kldload/8.md), [kldunload(8)](/man/kldunload/8.md)

## HISTORY

The **aio** facility appeared as a kernel option in FreeBSD 3.0. The **aio** kernel module appeared in FreeBSD 5.0.