path: root/Documentation/scsi
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authorStephen M. Cameron <scameron@beardog.cce.hp.com>2010-05-27 15:14:29 -0500
committerJames Bottomley <James.Bottomley@suse.de>2010-07-27 12:01:16 -0500
commit992ebcf14f3cf029b8d0da4f479d752c19d8c726 (patch)
tree4f44ec1e8332f89159186b9a2a1d302977b20717 /Documentation/scsi
parent873f339fc53750c1e715f5e1d2dfdb9869b7ea3f (diff)
[SCSI] hpsa: Add hpsa.txt to Documentation/scsi
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Diffstat (limited to 'Documentation/scsi')
1 files changed, 100 insertions, 0 deletions
diff --git a/Documentation/scsi/hpsa.txt b/Documentation/scsi/hpsa.txt
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+HPSA - Hewlett Packard Smart Array driver
+This file describes the hpsa SCSI driver for HP Smart Array controllers.
+The hpsa driver is intended to supplant the cciss driver for newer
+Smart Array controllers. The hpsa driver is a SCSI driver, while the
+cciss driver is a "block" driver. Actually cciss is both a block
+driver (for logical drives) AND a SCSI driver (for tape drives). This
+"split-brained" design of the cciss driver is a source of excess
+complexity and eliminating that complexity is one of the reasons
+for hpsa to exist.
+Supported devices:
+Smart Array P212
+Smart Array P410
+Smart Array P410i
+Smart Array P411
+Smart Array P812
+Smart Array P712m
+Smart Array P711m
+StorageWorks P1210m
+Additionally, older Smart Arrays may work with the hpsa driver if the kernel
+boot parameter "hpsa_allow_any=1" is specified, however these are not tested
+nor supported by HP with this driver. For older Smart Arrays, the cciss
+driver should still be used.
+HPSA specific entries in /sys
+ In addition to the generic SCSI attributes available in /sys, hpsa supports
+ the following attributes:
+ HPSA specific host attributes:
+ ------------------------------
+ /sys/class/scsi_host/host*/rescan
+ the host "rescan" attribute is a write only attribute. Writing to this
+ attribute will cause the driver to scan for new, changed, or removed devices
+ (e.g. hot-plugged tape drives, or newly configured or deleted logical drives,
+ etc.) and notify the SCSI midlayer of any changes detected. Normally this is
+ triggered automatically by HP's Array Configuration Utility (either the GUI or
+ command line variety) so for logical drive changes, the user should not
+ normally have to use this. It may be useful when hot plugging devices like
+ tape drives, or entire storage boxes containing pre-configured logical drives.
+ HPSA specific disk attributes:
+ ------------------------------
+ /sys/class/scsi_disk/c:b:t:l/device/unique_id
+ /sys/class/scsi_disk/c:b:t:l/device/raid_level
+ /sys/class/scsi_disk/c:b:t:l/device/lunid
+ (where c:b:t:l are the controller, bus, target and lun of the device)
+ For example:
+ root@host:/sys/class/scsi_disk/4:0:0:0/device# cat unique_id
+ 600508B1001044395355323037570F77
+ root@host:/sys/class/scsi_disk/4:0:0:0/device# cat lunid
+ 0x0000004000000000
+ root@host:/sys/class/scsi_disk/4:0:0:0/device# cat raid_level
+ RAID 0
+HPSA specific ioctls:
+ For compatibility with applications written for the cciss driver, many, but
+ not all of the ioctls supported by the cciss driver are also supported by the
+ hpsa driver. The data structures used by these are described in
+ include/linux/cciss_ioctl.h
+ The above three ioctls all do exactly the same thing, which is to cause the driver
+ to rescan for new devices. This does exactly the same thing as writing to the
+ hpsa specific host "rescan" attribute.
+ Returns PCI domain, bus, device and function and "board ID" (PCI subsystem ID).
+ Returns driver version in three bytes encoded as:
+ (major_version << 16) | (minor_version << 8) | (subminor_version)
+ Allows "BMIC" and "CISS" commands to be passed through to the Smart Array.
+ These are used extensively by the HP Array Configuration Utility, SNMP storage
+ agents, etc. See cciss_vol_status at http://cciss.sf.net for some examples.

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