FreeBSD/Linux Kernel Cross Reference
sys/Documentation/cciss.txt

     This driver is for Compaq's SMART Array Controllers.
     
     Supported Cards:
     ----------------
     
     This driver is known to work with the following cards:
     
             * SA 5300
             * SA 5i 
            * SA 532
            * SA 5312
            * SA 641
            * SA 642
            * SA 6400
            * SA 6400 U320 Expansion Module
    
    If nodes are not already created in the /dev/cciss directory
    
    # mkdev.cciss [ctlrs]
    
    Where ctlrs is the number of controllers you have (defaults to 1 if not
    specified).
    
    Device Naming:
    --------------
    
    You need some entries in /dev for the cciss device.  The mkdev.cciss script
    can make device nodes for you automatically.  Currently the device setup
    is as follows:
    
    Major numbers:
            104     cciss0  
            105     cciss1  
            106     cciss2 
            etc...
    
    Minor numbers:
            b7 b6 b5 b4 b3 b2 b1 b0
            |----+----| |----+----|
                 |           |
                 |           +-------- Partition ID (0=wholedev, 1-15 partition)
                 |
                 +-------------------- Logical Volume number
    
    The suggested device naming scheme is:
    /dev/cciss/c0d0                 Controller 0, disk 0, whole device
    /dev/cciss/c0d0p1               Controller 0, disk 0, partition 1
    /dev/cciss/c0d0p2               Controller 0, disk 0, partition 2
    /dev/cciss/c0d0p3               Controller 0, disk 0, partition 3
    
    /dev/cciss/c1d1                 Controller 1, disk 1, whole device
    /dev/cciss/c1d1p1               Controller 1, disk 1, partition 1
    /dev/cciss/c1d1p2               Controller 1, disk 1, partition 2
    /dev/cciss/c1d1p3               Controller 1, disk 1, partition 3
    
    SCSI tape drive and medium changer support
    ------------------------------------------
    
    SCSI sequential access devices and medium changer devices are supported and 
    appropriate device nodes are automatically created.  (e.g.  
    /dev/st0, /dev/st1, etc.  See the "st" man page for more details.) 
    You must enable "SCSI tape drive support for Smart Array 5xxx" and 
    "SCSI support" in your kernel configuration to be able to use SCSI
    tape drives with your Smart Array 5xxx controller.
    
    Additionally, note that the driver will not engage the SCSI core at init 
    time.  The driver must be directed to dynamically engage the SCSI core via 
    the /proc filesystem entry which the "block" side of the driver creates as 
    /proc/driver/cciss/cciss* at runtime.  This is because at driver init time, 
    the SCSI core may not yet be initialized (because the driver is a block 
    driver) and attempting to register it with the SCSI core in such a case 
    would cause a hang.  This is best done via an initialization script 
    (typically in /etc/init.d, but could vary depending on distibution). 
    For example:
    
            for x in /proc/driver/cciss/cciss[0-9]*
            do
                    echo "engage scsi" > $x
            done
    
    Once the SCSI core is engaged by the driver, it cannot be disengaged 
    (except by unloading the driver, if it happens to be linked as a module.)
    
    Note also that if no sequential access devices or medium changers are
    detected, the SCSI core will not be engaged by the action of the above
    script.
    
    Hot plug support for SCSI tape drives
    -------------------------------------
    
    Hot plugging of SCSI tape drives is supported, with some caveats.
    The cciss driver must be informed that changes to the SCSI bus
    have been made, in addition to and prior to informing the SCSI 
    mid layer.  This may be done via the /proc filesystem.  For example:
    
            echo "rescan" > /proc/scsi/cciss0/1
    
    This causes the adapter to query the adapter about changes to the 
    physical SCSI buses and/or fibre channel arbitrated loop and the 
   driver to make note of any new or removed sequential access devices
   or medium changers.  The driver will output messages indicating what 
   devices have been added or removed and the controller, bus, target and 
   lun used to address the device.  Once this is done, the SCSI mid layer 
   can be informed of changes to the virtual SCSI bus which the driver 
   presents to it in the usual way. For example: 
   
           echo scsi add-single-device 3 2 1 0 > /proc/scsi/scsi
    
   to add a device on controller 3, bus 2, target 1, lun 0.   Note that
   the driver makes an effort to preserve the devices positions
   in the virtual SCSI bus, so if you are only moving tape drives 
   around on the same adapter and not adding or removing tape drives 
   from the adapter, informing the SCSI mid layer may not be necessary.
   
   Note that the naming convention of the /proc filesystem entries 
   contains a number in addition to the driver name.  (E.g. "cciss0" 
   instead of just "cciss" which you might expect.)   This is because 
   of changes to the 2.4 kernel PCI interface related to PCI hot plug
   that imply the driver must register with the SCSI mid layer once per
   adapter instance rather than once per driver.
   
   Note: ONLY sequential access devices and medium changers are presented 
   as SCSI devices to the SCSI mid layer by the cciss driver.  Specifically, 
   physical SCSI disk drives are NOT presented to the SCSI mid layer.  The 
   physical SCSI disk drives are controlled directly by the array controller 
   hardware and it is important to prevent the OS from attempting to directly 
   access these devices too, as if the array controller were merely a SCSI 
   controller in the same way that we are allowing it to access SCSI tape drives.
   

Cache object: 4a2e20aeed96bd8e3ca81e55c620d8af