nfsiod(8)

nfsiod8

Local nfs asynchronous i/o server

Usage

nfsiod [-n num_servers]

Overview

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). 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.

Releases

87 releases since FreeBSD 2.0.5-RELEASE; the text changed 49 times.

  1. 2.0.5
  2. 2.1.5–2.1.7.1
  3. 2.2.2–2.2.6
  4. 2.2.7–2.2.8
  5. 2.2.9
  6. 3.0–3.1
  7. 3.2
  8. 3.3–3.5.1
  9. 4.0–4.2
  10. 4.3–4.4
  11. 4.5–4.7
  12. 4.8
  13. 4.9–4.11
  14. 5.0–5.1
  15. 5.2–5.2.1
  16. 5.3–5.5
  17. 6.0–6.3
  18. 6.4
  19. 7.0
  20. 7.1
  21. 7.2
  22. 7.3
  23. 7.4
  24. 8.0
  25. 8.1
  26. 8.2
  27. 8.3
  28. 8.4
  29. 9.0
  30. 9.1
  31. 9.2
  32. 9.3
  33. 10.0
  34. 10.1
  35. 10.2
  36. 10.3
  37. 10.4
  38. 11.0
  39. 11.1
  40. 11.2
  41. 11.3
  42. 11.4
  43. 12.0
  44. 12.1
  45. 12.2
  46. 12.3
  47. 12.4
  48. 13.0–13.2
  49. 13.3–14.5
  50. 15.0–16.0

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) wrapper.

From base 16.0-CURRENT-20261027-61c70dc16a79 in FreeBSD 16.0-CURRENT (2026-10-27). Parsed by carta from the page's mdoc source.