CCISS(4) Linux Programmer's Manual CCISS(4)
NAME
cciss - HP Smart Array block driver
SYNOPSIS
modprobe cciss [ cciss_allow_hpsa=1 ]
DESCRIPTION
cciss 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 that the hpsa(4) driver is capable of con-
trolling, 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
Utility (either hpacuxe(8) or hpacucli(8)) or the Offline ROM-based
Configuration 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:
$ cd /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
$ 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
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
When this file is written to, the driver rescans the controller
to discover any new, removed, or modified logical drives.
/sys/bus/pci/devices/<dev>/ccissX/resettable
A value of 1 displayed in this file indicates that the
"reset_devices=1" kernel parameter (used by kdump) is honored by
this controller. A value of 0 indicates that the
"reset_devices=1" kernel parameter will not be honored. Some
models of Smart Array are not able to honor this parameter.
/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 st(4) 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 file-system entry, which the "block" side of the
driver creates as /proc/driver/cciss/cciss* at run time. 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 file system. For example:
echo "rescan" > /proc/scsi/cciss0/1
This causes the driver to:
1. query the adapter about changes to the physical SCSI buses
and/or fibre channel arbitrated loop, and
2. make note of any new or removed sequential access devices or
medium changers.
The driver will output messages indicating which devices have been
added or removed and the controller, bus, target and lun used to
address each device. The driver then notifies the SCSI midlayer of
these changes.
Note that the naming convention of the /proc file-system 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 midlayer by the cciss driver. Specifi-
cally, physical SCSI disk drives are not presented to the SCSI mid-
layer. The only disk devices that are presented to the kernel are log-
ical drives that the array controller constructs from regions on the
physical drives. The logical drives are presented to the block layer
(not to the SCSI midlayer). It is important for the driver to prevent
the kernel from accessing the physical drives directly, since these
drives are used by the array controller to construct the logical
drives.
SCSI error handling for tape drives and medium changers
The Linux SCSI midlayer provides an error-handling protocol that is
initiated 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 proto-
col 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.
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 midlayer
Furthermore, unlike more straightforward SCSI drivers, disk I/O contin-
ues through the block side during the SCSI error-recovery process
Therefore, the cciss driver implements only the first two of these
actions, aborting the command, and resetting the device. Note also
that most tape drives will not oblige in aborting commands, and some-
times it appears they will not even obey a reset command, though in
most circumstances they will. If the command cannot be aborted and the
device cannot be reset, the device will be set offline.
In the event that 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 that 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 that was reset.
SEE ALSO
cciss_vol_status(8), hpsa(4), hpacucli(8), hpacuxe(8),
<http://cciss.sf.net>;, and Documentation/blockdev/cciss.txt and Docu-
mentation/ABI/testing/sysfs-bus-pci-devices-cciss in the Linux kernel
source tree
COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2012-08-05 CCISS(4)
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