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     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



     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 Corporation.

     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 supports the “simple” and “performant” transport layer.

     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 and notification messages will be reported to the console and logs.

     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 ciss driver include:

        Compaq Smart Array 5300 (simple mode only)
        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 P220i
        HP Smart Array P222
        HP Smart Array P230i
        HP Smart Array P400
        HP Smart Array P400i
        HP Smart Array P410
        HP Smart Array P410i
        HP Smart Array P411
        HP Smart Array P420
        HP Smart Array P420i
        HP Smart Array P421
        HP Smart Array P430
        HP Smart Array P430i
        HP Smart Array P431
        HP Smart Array P530
        HP Smart Array P531
        HP Smart Array P600
        HP Smart Array P721m
        HP Smart Array P731m
        HP Smart Array P800
        HP Smart Array P812
        HP Smart Array P830
        HP Smart Array P830i
        HP Modular Smart Array 20 (MSA20)
        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