Documentation/scsi/hpsa.txt

   1
   2 HPSA - Hewlett Packard Smart Array driver
   3 -----------------------------------------
   4
   5 This file describes the hpsa SCSI driver for HP Smart Array controllers.
   6 The hpsa driver is intended to supplant the cciss driver for newer
   7 Smart Array controllers.  The hpsa driver is a SCSI driver, while the
   8 cciss driver is a "block" driver.  Actually cciss is both a block
   9 driver (for logical drives) AND a SCSI driver (for tape drives). This
  10 "split-brained" design of the cciss driver is a source of excess
  11 complexity and eliminating that complexity is one of the reasons
  12 for hpsa to exist.
  13
  14 Supported devices:
  15 ------------------
  16
  17 Smart Array P212
  18 Smart Array P410
  19 Smart Array P410i
  20 Smart Array P411
  21 Smart Array P812
  22 Smart Array P712m
  23 Smart Array P711m
  24 StorageWorks P1210m
  25
  26 Additionally, older Smart Arrays may work with the hpsa driver if the kernel
  27 boot parameter "hpsa_allow_any=1" is specified, however these are not tested
  28 nor supported by HP with this driver.  For older Smart Arrays, the cciss
  29 driver should still be used.
  30
  31 The "hpsa_simple_mode=1" boot parameter may be used to prevent the driver from
  32 putting the controller into "performant" mode.  The difference is that with simple
  33 mode, each command completion requires an interrupt, while with "performant mode"
  34 (the default, and ordinarily better performing) it is possible to have multiple
  35 command completions indicated by a single interrupt.
  36
  37 HPSA specific entries in /sys
  38 -----------------------------
  39
  40   In addition to the generic SCSI attributes available in /sys, hpsa supports
  41   the following attributes:
  42
  43   HPSA specific host attributes:
  44   ------------------------------
  45
  46   /sys/class/scsi_host/host*/rescan
  47   /sys/class/scsi_host/host*/firmware_revision
  48   /sys/class/scsi_host/host*/resettable
  49   /sys/class/scsi_host/host*/transport_mode
  50
  51   the host "rescan" attribute is a write only attribute.  Writing to this
  52   attribute will cause the driver to scan for new, changed, or removed devices
  53   (e.g. hot-plugged tape drives, or newly configured or deleted logical drives,
  54   etc.) and notify the SCSI midlayer of any changes detected.  Normally this is
  55   triggered automatically by HP's Array Configuration Utility (either the GUI or
  56   command line variety) so for logical drive changes, the user should not
  57   normally have to use this.  It may be useful when hot plugging devices like
  58   tape drives, or entire storage boxes containing pre-configured logical drives.
  59
  60   The "firmware_revision" attribute contains the firmware version of the Smart Array.
  61   For example:
  62
  63         root@host:/sys/class/scsi_host/host4# cat firmware_revision
  64         7.14
  65
  66   The transport_mode indicates whether the controller is in "performant"
  67   or "simple" mode.  This is controlled by the "hpsa_simple_mode" module
  68   parameter.
  69
  70   The "resettable" read-only attribute indicates whether a particular
  71   controller is able to honor the "reset_devices" kernel parameter.  If the
  72   device is resettable, this file will contain a "1", otherwise, a "0".  This
  73   parameter is used by kdump, for example, to reset the controller at driver
  74   load time to eliminate any outstanding commands on the controller and get the
  75   controller into a known state so that the kdump initiated i/o will work right
  76   and not be disrupted in any way by stale commands or other stale state
  77   remaining on the controller from the previous kernel.  This attribute enables
  78   kexec tools to warn the user if they attempt to designate a device which is
  79   unable to honor the reset_devices kernel parameter as a dump device.
  80
  81   HPSA specific disk attributes:
  82   ------------------------------
  83
  84   /sys/class/scsi_disk/c:b:t:l/device/unique_id
  85   /sys/class/scsi_disk/c:b:t:l/device/raid_level
  86   /sys/class/scsi_disk/c:b:t:l/device/lunid
  87
  88   (where c:b:t:l are the controller, bus, target and lun of the device)
  89
  90   For example:
  91
  92         root@host:/sys/class/scsi_disk/4:0:0:0/device# cat unique_id
  93         600508B1001044395355323037570F77
  94         root@host:/sys/class/scsi_disk/4:0:0:0/device# cat lunid
  95         0x0000004000000000
  96         root@host:/sys/class/scsi_disk/4:0:0:0/device# cat raid_level
  97         RAID 0
  98
  99 HPSA specific ioctls:
 100 ---------------------
 101
 102   For compatibility with applications written for the cciss driver, many, but
 103   not all of the ioctls supported by the cciss driver are also supported by the
 104   hpsa driver.  The data structures used by these are described in
 105   include/linux/cciss_ioctl.h
 106
 107   CCISS_DEREGDISK
 108   CCISS_REGNEWDISK
 109   CCISS_REGNEWD
 110
 111   The above three ioctls all do exactly the same thing, which is to cause the driver
 112   to rescan for new devices.  This does exactly the same thing as writing to the
 113   hpsa specific host "rescan" attribute.
 114
 115   CCISS_GETPCIINFO
 116
 117         Returns PCI domain, bus, device and function and "board ID" (PCI subsystem ID).
 118
 119   CCISS_GETDRIVVER
 120
 121         Returns driver version in three bytes encoded as:
 122                 (major_version << 16) | (minor_version << 8) | (subminor_version)
 123
 124   CCISS_PASSTHRU
 125   CCISS_BIG_PASSTHRU
 126
 127         Allows "BMIC" and "CISS" commands to be passed through to the Smart Array.
 128         These are used extensively by the HP Array Configuration Utility, SNMP storage
 129         agents, etc.  See cciss_vol_status at http://cciss.sf.net for some examples.
 130