man4/cciss.4

   1 .\" Copyright (C) 2011, Hewlett-Packard Development Company, L.P.
   2 .\" Written by Stephen M. Cameron <scameron@beardog.cce.hp.com>
   3 .\" Licensed under GNU General Public License version 2 (GPLv2)
   4 .\"
   5 .\" shorthand for double quote that works everywhere.
   6 .ds q \N'34'
   7 .TH CCISS 4  2011-09-21 "Linux" "Linux Programmer's Manual"
   8 .SH NAME
   9 cciss \- HP Smart Array block driver
  10 .SH SYNOPSIS
  11 .nf
  12 modprobe cciss [ cciss_allow_hpsa=1 ]
  13 .fi
  14 .SH DESCRIPTION
  15 .B cciss
  16 is a block driver for older HP Smart Array RAID controllers.
  17 .SS Options
  18 .IR "cciss_allow_hpsa=1" :
  19 This option prevents the cciss driver
  20 from attempting to drive any controllers which the hpsa driver
  21 is capable of controlling, which is to say, the cciss driver
  22 is restricted by this option to the following controllers:
  23 .nf
  24
  25     Smart Array 5300
  26     Smart Array 5i
  27     Smart Array 532
  28     Smart Array 5312
  29     Smart Array 641
  30     Smart Array 642
  31     Smart Array 6400
  32     Smart Array 6400 EM
  33     Smart Array 6i
  34     Smart Array P600
  35     Smart Array P400i
  36     Smart Array E200i
  37     Smart Array E200
  38     Smart Array E200i
  39     Smart Array E200i
  40     Smart Array E200i
  41     Smart Array E500
  42 .fi
  43 .SS Supported Hardware
  44 The
  45 .B cciss
  46 driver supports the following Smart Array boards:
  47 .nf
  48
  49     Smart Array 5300
  50     Smart Array 5i
  51     Smart Array 532
  52     Smart Array 5312
  53     Smart Array 641
  54     Smart Array 642
  55     Smart Array 6400
  56     Smart Array 6400 U320 Expansion Module
  57     Smart Array 6i
  58     Smart Array P600
  59     Smart Array P800
  60     Smart Array E400
  61     Smart Array P400i
  62     Smart Array E200
  63     Smart Array E200i
  64     Smart Array E500
  65     Smart Array P700m
  66     Smart Array P212
  67     Smart Array P410
  68     Smart Array P410i
  69     Smart Array P411
  70     Smart Array P812
  71     Smart Array P712m
  72     Smart Array P711m
  73 .fi
  74 .SS Configuration Details
  75 To configure HP Smart Array controllers,
  76 use the HP Array Configuration Utility
  77 (either hpacuxe or hpacucli) or
  78 the Offline ROM-based Configuration Utility (ORCA)
  79 run from the Smart Array's option ROM at boot time.
  80 .SH FILES
  81 .SS Device Nodes
  82 The device naming scheme is as follows:
  83 .nf
  84
  85 Major numbers:
  86
  87     104     cciss0
  88     105     cciss1
  89     106     cciss2
  90     105     cciss3
  91     108     cciss4
  92     109     cciss5
  93     110     cciss6
  94     111     cciss7
  95
  96 Minor numbers:
  97
  98     b7 b6 b5 b4 b3 b2 b1 b0
  99     |----+----| |----+----|
 100          |           |
 101          |           +-------- Partition ID (0=wholedev, 1-15 partition)
 102          |
 103          +-------------------- Logical Volume number
 104
 105 The device naming scheme is:
 106
 107     /dev/cciss/c0d0         Controller 0, disk 0, whole device
 108     /dev/cciss/c0d0p1       Controller 0, disk 0, partition 1
 109     /dev/cciss/c0d0p2       Controller 0, disk 0, partition 2
 110     /dev/cciss/c0d0p3       Controller 0, disk 0, partition 3
 111
 112     /dev/cciss/c1d1         Controller 1, disk 1, whole device
 113     /dev/cciss/c1d1p1       Controller 1, disk 1, partition 1
 114     /dev/cciss/c1d1p2       Controller 1, disk 1, partition 2
 115     /dev/cciss/c1d1p3       Controller 1, disk 1, partition 3
 116
 117 .fi
 118 .SS Files in /proc
 119 The files
 120 .I /proc/driver/cciss/cciss[0-9]+
 121 contain information about
 122 the configuration of each controller.
 123 For example:
 124 .nf
 125
 126     $ \fBcd /proc/driver/cciss\fP
 127     $ \fBls -l\fP
 128     total 0
 129     -rw-r--r-- 1 root root 0 2010-09-10 10:38 cciss0
 130     -rw-r--r-- 1 root root 0 2010-09-10 10:38 cciss1
 131     -rw-r--r-- 1 root root 0 2010-09-10 10:38 cciss2
 132     $ \fBcat cciss2\fP
 133     cciss2: HP Smart Array P800 Controller
 134     Board ID: 0x3223103c
 135     Firmware Version: 7.14
 136     IRQ: 16
 137     Logical drives: 1
 138     Current Q depth: 0
 139     Current # commands on controller: 0
 140     Max Q depth since init: 1
 141     Max # commands on controller since init: 2
 142     Max SG entries since init: 32
 143     Sequential access devices: 0
 144
 145     cciss/c2d0:   36.38GB       RAID 0
 146
 147 .fi
 148 .SS Files in /sys
 149
 150 .TP
 151 .I /sys/bus/pci/devices/<dev>/ccissX/cXdY/model
 152 Displays the SCSI INQUIRY page 0 model for logical drive Y of controller X.
 153 .TP
 154 .I /sys/bus/pci/devices/<dev>/ccissX/cXdY/rev
 155 Displays the SCSI INQUIRY page 0 revision for logical drive Y of controller X.
 156 .TP
 157 .I /sys/bus/pci/devices/<dev>/ccissX/cXdY/unique_id
 158 Displays the SCSI INQUIRY page 83 serial number for
 159 logical drive Y of controller X.
 160 .TP
 161 .I /sys/bus/pci/devices/<dev>/ccissX/cXdY/vendor
 162 Displays the SCSI INQUIRY page 0 vendor for logical drive Y of controller X.
 163 .TP
 164 .I /sys/bus/pci/devices/<dev>/ccissX/cXdY/block:cciss!cXdY
 165 A symbolic link to /sys/block/cciss!cXdY
 166 .TP
 167 .I /sys/bus/pci/devices/<dev>/ccissX/rescan
 168 Kicks off a rescan of the controller to discover logical drive topology changes.
 169 .TP
 170 .I /sys/bus/pci/devices/<dev>/ccissX/resettable
 171 A value of 1 indicates the "reset_devices=1" kernel parameter (used by
 172 kdump) is honored by this controller.
 173 A value of 0 indicates the
 174 "reset_devices=1" kernel parameter will not be honored.
 175 Some models of Smart Array are not able to honor this parameter.
 176 .TP
 177 .I /sys/bus/pci/devices/<dev>/ccissX/cXdY/lunid
 178 Displays the 8-byte LUN ID used to address logical drive Y of controller X.
 179 .TP
 180 .I /sys/bus/pci/devices/<dev>/ccissX/cXdY/raid_level
 181 Displays the RAID level of logical drive Y of controller X.
 182 .TP
 183 .I /sys/bus/pci/devices/<dev>/ccissX/cXdY/usage_count
 184 Displays the usage count (number of opens) of logical drive Y of controller X.
 185 .SS SCSI tape drive and medium changer support
 186 SCSI sequential access devices and medium changer devices are supported and
 187 appropriate device nodes are automatically created (e.g.
 188 .IR /dev/st0 ,
 189 .IR /dev/st1
 190 etc.; see
 191 .BR st (4)
 192 for more details.)
 193 You must enable "SCSI tape drive support for Smart Array 5xxx" and
 194 "SCSI support" in your kernel configuration to be able to use SCSI
 195 tape drives with your Smart Array 5xxx controller.
 196
 197 Additionally, note that the driver will not engage the SCSI core at init time.
 198 The driver must be directed to dynamically engage the SCSI core via
 199 the /proc filesystem entry which the "block" side of the driver creates as
 200 /proc/driver/cciss/cciss* at runtime.
 201 This is because at driver init time,
 202 the SCSI core may not yet be initialized (because the driver is a block
 203 driver) and attempting to register it with the SCSI core in such a case
 204 would cause a hang.
 205 This is best done via an initialization script
 206 (typically in
 207 .IR /etc/init.d ,
 208 but could vary depending on distribution).
 209 For example:
 210 .nf
 211
 212     for x in /proc/driver/cciss/cciss[0-9]*
 213     do
 214         echo "engage scsi" > $x
 215     done
 216
 217 .fi
 218 Once the SCSI core is engaged by the driver, it cannot be disengaged
 219 (except by unloading the driver, if it happens to be linked as a module.)
 220
 221 Note also that if no sequential access devices or medium changers are
 222 detected, the SCSI core will not be engaged by the action of the above
 223 script.
 224
 225 .SS Hot plug support for SCSI tape drives
 226
 227 Hot plugging of SCSI tape drives is supported, with some caveats.
 228 The cciss driver must be informed that changes to the SCSI bus
 229 have been made.
 230 This may be done via the /proc filesystem.
 231 For example:
 232
 233     echo "rescan" > /proc/scsi/cciss0/1
 234
 235 This causes the driver to query the adapter about changes to the
 236 physical SCSI buses and/or fibre channel arbitrated loop and the
 237 driver to make note of any new or removed sequential access devices
 238 or medium changers.
 239 The driver will output messages indicating what
 240 devices have been added or removed and the controller, bus, target and
 241 lun used to address the device.
 242 It then notifies the SCSI mid layer
 243 of these changes.
 244
 245 Note that the naming convention of the /proc filesystem entries
 246 contains a number in addition to the driver name
 247 (e.g., "cciss0"
 248 instead of just "cciss" which you might expect).
 249
 250 Note:
 251 .I Only
 252 sequential access devices and medium changers are presented
 253 as SCSI devices to the SCSI mid layer by the cciss driver.
 254 Specifically, physical SCSI disk drives are
 255 .I not
 256 presented to the SCSI mid layer.
 257 The physical SCSI disk drives are controlled directly by the array controller
 258 hardware and it is important to prevent the kernel from attempting to directly
 259 access these devices too, as if the array controller were merely a SCSI
 260 controller in the same way that we are allowing it to access SCSI tape drives.
 261 .SS SCSI error handling for tape drives and medium changers
 262 The linux SCSI mid layer provides an error handling protocol which
 263 kicks into gear whenever a SCSI command fails to complete within a
 264 certain amount of time (which can vary depending on the command).
 265 The cciss driver participates in this protocol to some extent.
 266 The normal protocol is a four step process.
 267 First the device is told to abort the command.
 268 If that doesn't work, the device is reset.
 269 If that doesn't work, the SCSI bus is reset.
 270 If that doesn't work the host bus adapter is reset.
 271 Because the cciss driver is a block
 272 driver as well as a SCSI driver and only the tape drives and medium
 273 changers are presented to the SCSI mid layer, and unlike more
 274 straightforward SCSI drivers, disk i/o continues through the block
 275 side during the SCSI error recovery process, the cciss driver only
 276 implements the first two of these actions, aborting the command, and
 277 resetting the device.
 278 Additionally, most tape drives will not oblige
 279 in aborting commands, and sometimes it appears they will not even
 280 obey a reset command, though in most circumstances they will.
 281 In the case that the command cannot be aborted and the device cannot be
 282 reset, the device will be set offline.
 283
 284 In the event the error handling code is triggered and a tape drive is
 285 successfully reset or the tardy command is successfully aborted, the
 286 tape drive may still not allow i/o to continue until some command
 287 is issued which positions the tape to a known position.
 288 Typically you must rewind the tape (by issuing
 289 .I "mt -f /dev/st0 rewind"
 290 for example)
 291 before I/O can proceed again to a tape drive which was reset.
 292 .SH "SEE ALSO"
 293 .BR hpsa (4),
 294 .BR hpacucli (8),
 295 .BR hpacuxe (8),
 296 .BR cciss_vol_status (8),
 297 .IR http://cciss.sf.net ,
 298 and the linux kernel source files
 299 .I Documentation/blockdev/cciss.txt
 300 and
 301 .I Documentation/ABI/testing/sysfs-bus-pci-devices-cciss
 302 .\" .SH AUTHORS
 303 .\" Don Brace, Steve Cameron, Chase Maupin, Mike Miller, Michael Ni,
 304 .\" Charles White, Francis Wiran
 305 .\" and probably some other people.