man-pages/man4/cciss.4

.\" shorthand for double quote that works everywhere.
.ds q \N'34'
.TH CCISS 4 "cciss"
.SH NAME
cciss \- HP Smart Array block driver
.SH SYNOPSIS
.nf
modprobe cciss [ cciss_allow_hpsa=1 ]
.fi
.SH DESCRIPTION
.B cciss
is a block driver for older HP Smart Array RAID controllers.
.SH OPTIONS
.HP
cciss_allow_hpsa=1
This option prevents the cciss driver
from attempting to drive any controllers which the hpsa driver
is capable of controlling, which is to say, the cciss driver
is restricted by this option to the following controllers:
.nf

	Smart Array 5300
	Smart Array 5i
	Smart Array 532
	Smart Array 5312
	Smart Array 641
	Smart Array 642
	Smart Array 6400
	Smart Array 6400 EM
	Smart Array 6i
	Smart Array P600
	Smart Array P400i
	Smart Array E200i
	Smart Array E200
	Smart Array E200i
	Smart Array E200i
	Smart Array E200i
	Smart Array E500
.fi


.SH SUPPORTED HARDWARE
The
.B cciss
driver supports the following Smart Array boards:
.nf

	Smart Array 5300
	Smart Array 5i
	Smart Array 532
	Smart Array 5312
	Smart Array 641
	Smart Array 642
	Smart Array 6400
	Smart Array 6400 U320 Expansion Module
	Smart Array 6i
	Smart Array P600
	Smart Array P800
	Smart Array E400
	Smart Array P400i
	Smart Array E200
	Smart Array E200i
	Smart Array E500
	Smart Array P700m
	Smart Array P212
	Smart Array P410
	Smart Array P410i
	Smart Array P411
	Smart Array P812
	Smart Array P712m
	Smart Array P711m
.fi
.SH CONFIGURATION DETAILS
To configure HP Smart Array controllers, use the HP Array Configuration Utility
(either hpacuxe or hpacucli) or the Offline ROM-based Configuration Utility (ORCA)
run from the Smart Array's option ROM at boot time.
.SH FILES
.SS DEVICE NODES
The device naming scheme is as follows:
.nf
Major numbers:
        104     cciss0
        105     cciss1
        106     cciss2
        105     cciss3
        108     cciss4
        109     cciss5
        110     cciss6
        111     cciss7

Minor numbers:
        b7 b6 b5 b4 b3 b2 b1 b0
        |----+----| |----+----|
             |           |
             |           +-------- Partition ID (0=wholedev, 1-15 partition)
             |
             +-------------------- Logical Volume number

The 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

.fi
.SS FILES IN /proc
The files /proc/driver/cciss/cciss[0-9]+ contain information about
the configuration of each controller.  For example:
.nf

	someone@somehost:/proc/driver/cciss> ls -l
	total 0
	-rw-r--r-- 1 root root 0 2010-09-10 10:38 cciss0
	-rw-r--r-- 1 root root 0 2010-09-10 10:38 cciss1
	-rw-r--r-- 1 root root 0 2010-09-10 10:38 cciss2
	someone@somehost:/proc/driver/cciss> cat cciss2
	cciss2: HP Smart Array P800 Controller
	Board ID: 0x3223103c
	Firmware Version: 7.14
	IRQ: 16
	Logical drives: 1
	Current Q depth: 0
	Current # commands on controller: 0
	Max Q depth since init: 1
	Max # commands on controller since init: 2
	Max SG entries since init: 32
	Sequential access devices: 0

	cciss/c2d0:	  36.38GB	RAID 0
	someone@somehost:/proc/driver/cciss>

.fi
.SS FILES IN /sys

.HP
/sys/bus/pci/devices/<dev>/ccissX/cXdY/model

Displays the SCSI INQUIRY page 0 model for logical drive Y of controller X.

.HP
/sys/bus/pci/devices/<dev>/ccissX/cXdY/rev

Displays the SCSI INQUIRY page 0 revision for logical drive Y of controller X.

.HP
/sys/bus/pci/devices/<dev>/ccissX/cXdY/unique_id

Displays the SCSI INQUIRY page 83 serial number for logical drive Y of controller X.

.HP
/sys/bus/pci/devices/<dev>/ccissX/cXdY/vendor

Displays the SCSI INQUIRY page 0 vendor for logical drive Y of controller X.

.HP
/sys/bus/pci/devices/<dev>/ccissX/cXdY/block:cciss!cXdY

A symbolic link to /sys/block/cciss!cXdY

.HP
/sys/bus/pci/devices/<dev>/ccissX/rescan

Kicks off a rescan of the controller to discover logical drive topology changes.

.HP
/sys/bus/pci/devices/<dev>/ccissX/resettable

A value of 1 indicates the "reset_devices=1" kernel parameter (used by
kdump) is honored by this controller.  A value of 0 indicates the
"reset_devices=1" kernel parameter will not be honored.  Some models
of Smart Array are not able to honor this parameter.

.HP
/sys/bus/pci/devices/<dev>/ccissX/cXdY/lunid

Displays the 8-byte LUN ID used to address logical drive Y of controller X.

.HP
/sys/bus/pci/devices/<dev>/ccissX/cXdY/raid_level

Displays the RAID level of logical drive Y of controller X.

.HP
/sys/bus/pci/devices/<dev>/ccissX/cXdY/usage_count

Displays the usage count (number of opens) of logical drive Y of controller X.

.SH 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 distribution).
For example:
.nf

        for x in /proc/driver/cciss/cciss[0-9]*
        do
                echo "engage scsi" > $x
        done

.fi
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.

.SS 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.  This may be done via the /proc filesystem.
For example:

        echo "rescan" > /proc/scsi/cciss0/1

This causes the driver 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.  It then notifies the SCSI mid layer
of these changes.

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.)

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 kernel 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.

.SS SCSI error handling for tape drives and medium changers

The linux SCSI mid layer provides an error handling protocol which
kicks into gear whenever a SCSI command fails to complete within a
certain amount of time (which can vary depending on the command).
The cciss driver participates in this protocol to some extent.  The
normal protocol is a four step process.  First the device is told
to abort the command.  If that doesn't work, the device is reset.
If that doesn't work, the SCSI bus is reset.  If that doesn't work
the host bus adapter is reset.  Because the cciss driver is a block
driver as well as a SCSI driver and only the tape drives and medium
changers are presented to the SCSI mid layer, and unlike more
straightforward SCSI drivers, disk i/o continues through the block
side during the SCSI error recovery process, the cciss driver only
implements the first two of these actions, aborting the command, and
resetting the device.  Additionally, most tape drives will not oblige
in aborting commands, and sometimes it appears they will not even
obey a reset command, though in most circumstances they will.  In
the case that the command cannot be aborted and the device cannot be
reset, the device will be set offline.

In the event the error handling code is triggered and a tape drive is
successfully reset or the tardy command is successfully aborted, the
tape drive may still not allow i/o to continue until some command
is issued which positions the tape to a known position.  Typically you
must rewind the tape (by issuing "mt -f /dev/st0 rewind" for example)
before i/o can proceed again to a tape drive which was reset.

.SH "SEE ALSO"
hpsa(4), hpacucli(8), hpacuxe(8), cciss_vol_status(8), http://cciss.sf.net,
and from the linux kernel source, Documentation/blockdev/cciss.txt and
Documentation/ABI/testing/sysfs-bus-pci-devices-cciss
.SH AUTHORS
Don Brace, Steve Cameron, Chase Maupin, Mike Miller, Michael Ni, Charles White, Francis Wiran
and probably some other people.