ses —
SCSI Environmental Services Driver
ses* at scsibus? target ? lun ?
The ses driver provides support for all SCSI devices of
  the environmental services class that are attached to the system through a
  supported SCSI Host Adapter, as well as emulated support for SAF-TE (SCSI
  Accessible Fault Tolerant Enclosures). The environmental services class
  generally are enclosure devices that provide environmental information such as
  number of power supplies (and state), temperature, device slots, and so on.
A SCSI Host adapter must also be separately configured into the
    system before a SCSI Environmental Services device can be configured.
The following ioctl(2) calls apply
  to SES devices. They are defined in the header file
  <scsipi/ses.h> (q.v.).
  - SESIOC_GETNOBJ
- Used to find out how many SES objects are driven by this
      particular device instance.
- SESIOC_GETOBJMAP
- Read, from the kernel, an array of SES objects which contains the object
      identifier, which sub-enclosure it is in, and the SES
      type of the object.
- SESIOC_GETENCSTAT
- Get the overall enclosure status.
- SESIOC_SETENCSTAT
- Set the overall enclosure status.
- SESIOC_GETOBJSTAT
- Get the status of a particular object.
- SESIOC_SETOBJSTAT
- Set the status of a particular object.
- SESIOC_GETTEXT
- Get the associated help text for an object (not yet implemented).
      SES devices often have descriptive text for an object
      which can tell you things like location (e.g, "left power
      supply").
- SESIOC_INIT
- Initialize the enclosure.
  - /dev/sesN
- The Nth sesdevice.
When the kernel is configured with DEBUG enabled, the first open to an SES
  device will spit out overall enclosure parameters to the console.
Theses driver was written for the SCSI subsystem by
  Matthew Jacob. This is the functional equivalent of a similar driver available
  in Solaris, Release 7.