Ubuntu Manpage: cciss - HP Smart Array block driver

NAME

       cciss - HP Smart Array block driver

SYNOPSIS

       modprobe cciss [ cciss_allow_hpsa=1 ]

DESCRIPTION

       Note:  This  obsolete  driver  was  removed  from  the  kernel  in  version 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       superseded by the hpsa(4) driver in newer kernels.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.

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 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:

* 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 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.

COLOPHON

       This  page  is  part of release 5.13 of the Linux man-pages project.  A description of the
       project, information about reporting bugs, and the latest version of  this  page,  can  be
       found at https://www.kernel.org/doc/man-pages/.

NAME

SYNOPSIS

DESCRIPTION

FILES

SEE ALSO

COLOPHON