2 HPSA - Hewlett Packard Smart Array driver
3 -----------------------------------------
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
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.
31 HPSA specific entries in /sys
32 -----------------------------
34 In addition to the generic SCSI attributes available in /sys, hpsa supports
35 the following attributes:
37 HPSA specific host attributes:
38 ------------------------------
40 /sys/class/scsi_host/host*/rescan
41 /sys/class/scsi_host/host*/firmware_revision
43 the host "rescan" attribute is a write only attribute. Writing to this
44 attribute will cause the driver to scan for new, changed, or removed devices
45 (e.g. hot-plugged tape drives, or newly configured or deleted logical drives,
46 etc.) and notify the SCSI midlayer of any changes detected. Normally this is
47 triggered automatically by HP's Array Configuration Utility (either the GUI or
48 command line variety) so for logical drive changes, the user should not
49 normally have to use this. It may be useful when hot plugging devices like
50 tape drives, or entire storage boxes containing pre-configured logical drives.
52 The "firmware_revision" attribute contains the firmware version of the Smart Array.
55 root@host:/sys/class/scsi_host/host4# cat firmware_revision
58 HPSA specific disk attributes:
59 ------------------------------
61 /sys/class/scsi_disk/c:b:t:l/device/unique_id
62 /sys/class/scsi_disk/c:b:t:l/device/raid_level
63 /sys/class/scsi_disk/c:b:t:l/device/lunid
65 (where c:b:t:l are the controller, bus, target and lun of the device)
69 root@host:/sys/class/scsi_disk/4:0:0:0/device# cat unique_id
70 600508B1001044395355323037570F77
71 root@host:/sys/class/scsi_disk/4:0:0:0/device# cat lunid
73 root@host:/sys/class/scsi_disk/4:0:0:0/device# cat raid_level
79 For compatibility with applications written for the cciss driver, many, but
80 not all of the ioctls supported by the cciss driver are also supported by the
81 hpsa driver. The data structures used by these are described in
82 include/linux/cciss_ioctl.h
88 The above three ioctls all do exactly the same thing, which is to cause the driver
89 to rescan for new devices. This does exactly the same thing as writing to the
90 hpsa specific host "rescan" attribute.
94 Returns PCI domain, bus, device and function and "board ID" (PCI subsystem ID).
98 Returns driver version in three bytes encoded as:
99 (major_version << 16) | (minor_version << 8) | (subminor_version)
104 Allows "BMIC" and "CISS" commands to be passed through to the Smart Array.
105 These are used extensively by the HP Array Configuration Utility, SNMP storage
106 agents, etc. See cciss_vol_status at http://cciss.sf.net for some examples.