---
name: "nfsiod"
section: "8"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd", "macos"]
url: "https://new.carta.tech/nfsiod"
---

# nfsiod(8)

local NFS asynchronous I/O server

## NAME

**nfsiod** – local NFS asynchronous I/O server

## SYNOPSIS

**nfsiod** \[**-n** *num\_servers*\]

## DESCRIPTION

The **nfsiod** utility controls the maximum number of **nfsiod** kernel processes which run on an NFS client machine to service asynchronous I/O requests to its server. Having **nfsiod** kernel processes improves performance but is not required for correct operation.

The option is as follows:

- **-n**

  Specify how many processes are permitted to be started.

Without an option, **nfsiod** displays the current settings. A client should allow enough number of processes to handle its maximum level of concurrency, typically four to six.

If **nfsiod** detects that the running kernel does not include NFS support, it will attempt to load a kernel module containing NFS code, using [kldload(2)](/kldload/2.md). If this fails, or no NFS module was available, **nfsiod** exits with an error.

## EXIT STATUS

The **nfsiod** utility exits 0 on success, and \>0 if an error occurs.

## SEE ALSO

[nfsstat(1)](/nfsstat/1.md), [kldload(2)](/kldload/2.md), [nfssvc(2)](/nfssvc/2.md), [mountd(8)](/mountd/8.md), [nfsd(8)](/nfsd/8.md), [rpcbind(8)](/rpcbind/8.md)

## HISTORY

The **nfsiod** utility first appeared in 4.4BSD.

Starting with FreeBSD 5.0, the utility no longer starts daemons, but only serves as a vfs loader and [sysctl(3)](/sysctl/3.md) wrapper.