CCISS(4)CCISS(4)NAMEcciss - HP Smart Array block driver
SYNOPSIS
modprobe cciss [ cciss_allow_hpsa=1 ]
DESCRIPTIONcciss is a block driver for older HP Smart Array RAID controllers.
OPTIONS
cciss_allow_hpsa=1 This option prevents the cciss driver from attempt‐
ing 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:
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
SUPPORTED HARDWARE
The cciss driver supports the following Smart Array boards:
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
CONFIGURATION DETAILS
To configure HP Smart Array controllers, use the HP Array Configuration
Utiltiy (either hpacuxe or hpacucli) or the Offline ROM-based Configu‐
ration Utility (ORCA) run from the Smart Array's option ROM at boot
time.
FILES
DEVICE NODES
The device naming scheme is as follows:
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
FILES IN /proc
The files /proc/driver/cciss/cciss[0-9]+ contain information about the
configuration of each controller. For example:
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>
FILES IN /sys
/sys/bus/pci/devices/<dev>/ccissX/cXdY/model
Displays the SCSI INQUIRY page 0 model for logical drive Y of
controller X.
/sys/bus/pci/devices/<dev>/ccissX/cXdY/rev
Displays the SCSI INQUIRY page 0 revision for logical drive Y of
controller X.
/sys/bus/pci/devices/<dev>/ccissX/cXdY/unique_id
Displays the SCSI INQUIRY page 83 serial number for logical
drive Y of controller X.
/sys/bus/pci/devices/<dev>/ccissX/cXdY/vendor
Displays the SCSI INQUIRY page 0 vendor for logical drive Y of
controller X.
/sys/bus/pci/devices/<dev>/ccissX/cXdY/block:cciss!cXdY
A symbolic link to /sys/block/cciss!cXdY
/sys/bus/pci/devices/<dev>/ccissX/rescan
Kicks off a rescan of the controller to discover logical drive
topology changes.
/sys/bus/pci/devices/<dev>/ccissX/cXdY/lunid
Displays the 8-byte LUN ID used to address logical drive Y of
controller X.
/sys/bus/pci/devices/<dev>/ccissX/cXdY/raid_level
Displays the RAID level of logical drive Y of controller X.
/sys/bus/pci/devices/<dev>/ccissX/cXdY/usage_count
Displays the usage count (number of opens) of logical drive Y of
controller X.
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:
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 mod‐
ule.)
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. 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 physi‐
cal 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 con‐
tains 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. Specifi‐
cally, 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.
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 cer‐
tain 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 circum‐
stances 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.
SEE ALSOhpsa(4), hpacucli(8), hpacuxe(8), cciss_vol_status(8),
http://cciss.sf.net, and from the linux kernel source, Documenta‐
tion/blockdev/cciss.txt and Documentation/ABI/testing/sysfs-bus-pci-
devices-cciss
AUTHORS
Don Brace, Steve Cameron, Chase Maupin, Mike Miller, Michael Ni,
Charles White, Francis Wiran and probably some other people.
ccissCCISS(4)
