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CISS(4)                FreeBSD Kernel Interfaces Manual                CISS(4)

     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.conf(5):


     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-

     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.

     Controllers supported by the ciss driver include:

     o   Compaq Smart Array 5300
     o   Compaq Smart Array 532
     o   Compaq Smart Array 5i
     o   HP Smart Array 5312
     o   HP Smart Array 6i
     o   HP Smart Array 641
     o   HP Smart Array 642
     o   HP Smart Array 6400
     o   HP Smart Array 6400 EM
     o   HP Smart Array E200
     o   HP Smart Array E200i
     o   HP Smart Array P400
     o   HP Smart Array P400i
     o   HP Smart Array P600
     o   HP Smart Array P800
     o   HP Modular Smart Array 20 (MSA20)
     o   HP Modular Smart Array 500 (MSA500)

     cam(4), pass(4), xpt(4), loader.conf(5), camcontrol(8)

     CISS Command Interface for SCSI-3 Support Open Specification, Version
     1.04, Valence Number 1, Compaq Computer Corporation, 2000/11/27.

     The ciss driver was written by Mike Smith <>.

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

FreeBSD 6.2                    November 3, 2005                    FreeBSD 6.2


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