CISS(4) BSD Kernel Interfaces Manual CISS(4)NAMEciss — Common Interface for SCSI-3 Support driver
SYNOPSIS
device scbus
device cissDESCRIPTION
The ciss driver claims to provide a common interface between generic SCSI
transports and intelligent host adapters.
The ciss 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 Corpora‐
tion.
We provide a shim layer between the ciss 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 ciss_probe(), ciss_attach(), etc.
and via the CAM interface ciss_cam_action(), and ciss_cam_poll(). The
Compaq ciss adapters require faked responses to get reasonable behavior
out of them. In addition, the ciss 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 ciss 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.
Supported controllers include:
Compaq Smart Array 5300
Compaq Smart Array 532
Compaq Smart Array 5i
HP Smart Array 5312
HP Smart Array 6i
HP Smart Array 641
HP Smart Array 642
HP Smart Array 6400
HP Smart Array 6400 EM
HP Smart Array E200
HP Smart Array E200i
HP Smart Array P212
HP Smart Array P400
HP Smart Array P400i
HP Smart Array P410
HP Smart Array P410i
HP Smart Array P411
HP Smart Array P600
HP Smart Array P800
HP Smart Array P812
HP Modular Smart Array 20 (MSA20)
HP Modular Smart Array 500 (MSA500)
SEE ALSOcam(4), pass(4), xpt(4), camcontrol(8)
CISS Command Interface for SCSI-3 Support Open Specification, Version
1.04, Valence Number 1, Compaq Computer Corporation, 2000/11/27.
AUTHORS
The ciss driver was written by Mike Smith ⟨msmith@FreeBSD.org⟩.
This manual page is based on his comments and was written by Tom Rhodes
⟨trhodes@FreeBSD.org⟩.
BSD December 13, 2008 BSD
