---
name: "uk"
section: "4"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["openbsd"]
url: "https://new.carta.tech/uk"
---

# uk(4)

SCSI user-level driver

## NAME

**uk** – SCSI user-level driver

## SYNOPSIS

**uk\* at scsibus?**

## DESCRIPTION

The **uk** driver provides support for a process to address devices on the SCSI bus for which there is no configured driver.

A SCSI adapter must also be separately configured into the system before this driver makes sense.

## IOCTLS

The **uk** driver has no ioctls of its own but rather acts as a medium for the generic [scsi(4)](/scsi/4.md) ioctls. These are described in ⟨sys/scsiio.h⟩.

## FILES

- */dev/uk\[0-255\]*

  uk{x} is the 'xth' unknown device found.

## DIAGNOSTICS

All [scsi(4)](/scsi/4.md) debug ioctls work on **uk** devices.

## SEE ALSO

[cd(4)](/cd/4.md), [ch(4)](/ch/4.md), [scsi(4)](/scsi/4.md), [sd(4)](/sd/4.md), [st(4)](/st/4.md)

## HISTORY

The **uk** driver appeared in NetBSD 1.0.