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

# ses(4)

SCSI Enclosure Services

## NAME

**ses** – SCSI Enclosure Services

## SYNOPSIS

**ses\* at scsibus?**

## DESCRIPTION

The **ses** driver provides support for monitoring the various environmental sensors present in SCSI enclosures using the SCSI Enclosure Services command set. The hardware monitoring is accessed via the *hw.sensors* [sysctl(8)](/sysctl/8.md) variable.

SCSI devices have a fairly high level interface to the system and talk to it via a SCSI host adapter (e.g. [ahc(4)](/ahc/4.md)). A SCSI adapter must also be separately configured into the system before a SCSI enclosure can be configured.

When the SCSI adapter is probed during boot, the SCSI bus is scanned for devices. Any SCSI-2 devices of type “Enclosure service” or SCSI-3 devices of type “Processor” will be attached to the **ses** driver.

SES compliant devices can provide an arbitrary set of sensors which may include the following types:

| | | |
| --- | --- | --- |
| **Sensor** | **Units** | **Typical Use** |
| temp | uK | temperature |
| fan | RPM | fan |
| psu | On/Off | power supply |
| doorlock | On/Off | door lock |
| alarm | On/Off | enclosure alarm |

Sensor data is updated every 10 seconds.

## SEE ALSO

[intro(4)](/intro/4.md), scsibus(4), [sensorsd(8)](/sensorsd/8.md), [sysctl(8)](/sysctl/8.md)

## HISTORY

The **ses** driver first appeared in OpenBSD 3.8.

## AUTHORS

The **ses** driver was written by David Gwynne ⟨*dlg@openbsd.org*⟩.