Langue: en

Version: 300821 (debian - 07/07/09)

Section: 4 (Pilotes et protocoles réseau)

BSD mandoc


ciss - Common Interface for SCSI-3 Support driver


To compile this driver into the kernel, place the following lines in your kernel configuration file:
device scbus device ciss

Alternatively, to load the driver as a module at boot time, place the following line in loader.conf5:



The driver claims to provide a common interface between generic SCSI transports and intelligent host adapters.

The driver supports CISS as defined in the document entitled "CISS Command Interface for SCSI-3 Support Open Specification, Version 1.04, Valence Number 1" , dated 2000/11/27, produced by Compaq Computer Corporation.

We provide a shim layer between the interface and CAM(4), offloading most of the queueing and being-a-disk chores onto CAM. Entry to the driver is via the PCI bus attachment Fn ciss_probe , Fn ciss_attach , etc. and via the CAM interface Fn ciss_cam_action , and Fn ciss_cam_poll . The Compaq adapters require faked responses to get reasonable behavior out of them. In addition, the command set is by no means adequate to support the functionality of a RAID controller, and thus the supported Compaq adapters utilize portions of the control protocol from earlier Compaq adapter families.

Currently only supports the ``simple'' transport layer over PCI. This interface (ab)uses the I2O register set (specifically the post queues) to exchange commands with the adapter. Other interfaces are available, but we are not supposed to know about them, and it is dubious whether they would provide major performance improvements except under extreme load.

Non-disk devices (such as internal DATs and devices attached to the external SCSI bus) are supported as normal CAM devices provided that they are exported by the controller firmware and are not marked as being masked. Masked devices can be exposed by setting the hw.ciss.expose_hidden_physical tunable to non-zero at boot time. Direct Access devices (such as disk drives) are only exposed as pass(4) devices. Hot-insertion and removal of devices is supported but a bus rescan might be necessary.

The problem which adapter freezes with the message ``ADAPTER HEARTBEAT FAILED'' might be solved by updating the firmware and/or setting the hw.ciss.nop_message_heartbeat tunable to non-zero at boot time.


Controllers supported by the driver include:


cam(4), pass(4), xpt(4), loader.conf5, camcontrol(8)
"CISS Command Interface for SCSI-3 Support Open Specification, Version 1.04, Valence Number 1" 2000/11/27 "Compaq Computer Corporation"


An -nosplit The driver was written by An Mike Smith Aq .

This manual page is based on his comments and was written by An Tom Rhodes Aq .