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NAME | SYNOPSIS | DESCRIPTION | FILES | SEE ALSO |
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cciss(4) Kernel Interfaces Manual cciss(4)
cciss - HP Smart Array block driver
modprobe cciss [ cciss_allow_hpsa=1 ]
Note: This obsolete driver was removed in Linux 4.14, as it is
superseded by the hpsa(4) driver in newer kernels.
cciss is a block driver for older HP Smart Array RAID
controllers.
Options
cciss_allow_hpsa=1: This option prevents the cciss driver from
attempting to drive any controllers that the hpsa(4) 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 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.
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 filesystem 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 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. This may be done via the /proc filesystem. 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 fiber 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 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 midlayer by the cciss
driver. Specifically, physical SCSI disk drives are not
presented to the SCSI midlayer. The only disk devices that are
presented to the kernel are logical 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 protocol is a four-step process:
(1) First, the device is told to abort the command.
(2) If that doesn't work, the device is reset.
(3) If that doesn't work, the SCSI bus is reset.
(4) 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 continues 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 sometimes 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.
hpsa(4), cciss_vol_status(8), hpacucli(8), hpacuxe(8)
⟨http:https://cciss.sf.net⟩, and Documentation/blockdev/cciss.txt and
Documentation/ABI/testing/sysfs-bus-pci-devices-cciss in the
Linux kernel source tree
Linux man-pages (unreleased) (date) cciss(4)
Pages that refer to this page: hpsa(4), smartpqi(4), capabilities(7)
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HTML rendering created 2023-12-22 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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