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-This driver is for Compaq's SMART Array Controllers.
-
-Supported Cards:
-----------------
-
-This driver is known to work with the following cards:
-
- * SA 5300
- * SA 5i
- * SA 532
- * SA 5312
- * SA 641
- * SA 642
- * SA 6400
- * SA 6400 U320 Expansion Module
- * SA 6i
- * SA P600
- * SA P800
- * SA E400
- * SA P400i
- * SA E200
- * SA E200i
- * SA E500
- * SA P700m
- * SA P212
- * SA P410
- * SA P410i
- * SA P411
- * SA P812
- * SA P712m
- * SA P711m
-
-Detecting drive failures:
--------------------------
-
-To get the status of logical volumes and to detect physical drive
-failures, you can use the cciss_vol_status program found here:
-http://cciss.sourceforge.net/#cciss_utils
-
-Device Naming:
---------------
-
-If nodes are not already created in the /dev/cciss directory, run as root:
-
-# cd /dev
-# ./MAKEDEV cciss
-
-You need some entries in /dev for the cciss device. The MAKEDEV script
-can make device nodes for you automatically. Currently the device setup
-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
-
-CCISS simple mode support
--------------------------
-
-The "cciss_simple_mode=1" boot parameter may be used to prevent the driver
-from putting the controller into "performant" mode. The difference is that
-with simple mode, each command completion requires an interrupt, while with
-"performant mode" (the default, and ordinarily better performing) it is
-possible to have multiple command completions indicated by a single
-interrupt.
-
-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 the "st" man page 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 engage the SCSI core at init
-time if any tape drives or medium changers are detected. The driver may
-also 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 runtime. This is best done via a script.
-
-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 query the adapter about changes to the
-physical SCSI buses and/or fibre channel arbitrated loop and the
-driver to make note of any new or removed sequential access devices
-or medium changers. The driver will output messages indicating what
-devices have been added or removed and the controller, bus, target and
-lun used to address the device. It then notifies the SCSI mid layer
-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 mid layer by the cciss driver. Specifically,
-physical SCSI disk drives are NOT presented to the SCSI mid layer. The
-physical SCSI disk drives are controlled directly by the array controller
-hardware and it is important to prevent the kernel from attempting to directly
-access these devices too, as if the array controller were merely a SCSI
-controller in the same way that we are allowing it to access SCSI tape drives.
-
-SCSI error handling for tape drives and medium changers
--------------------------------------------------------
-
-The linux SCSI mid layer provides an error handling protocol which
-kicks into gear 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. Because 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 mid layer, and unlike more
-straightforward SCSI drivers, disk i/o continues through the block
-side during the SCSI error recovery process, the cciss driver only
-implements the first two of these actions, aborting the command, and
-resetting the device. Additionally, 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. In
-the case that the command cannot be aborted and the device cannot be
-reset, the device will be set offline.
-
-In the event 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 which 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 which was reset.
-
-There is a cciss_tape_cmds module parameter which can be used to make cciss
-allocate more commands for use by tape drives. Ordinarily only a few commands
-(6) are allocated for tape drives because tape drives are slow and
-infrequently used and the primary purpose of Smart Array controllers is to
-act as a RAID controller for disk drives, so the vast majority of commands
-are allocated for disk devices. However, if you have more than a few tape
-drives attached to a smart array, the default number of commands may not be
-enought (for example, if you have 8 tape drives, you could only rewind 6
-at one time with the default number of commands.) The cciss_tape_cmds module
-parameter allows more commands (up to 16 more) to be allocated for use by
-tape drives. For example:
-
- insmod cciss.ko cciss_tape_cmds=16
-
-Or, as a kernel boot parameter passed in via grub: cciss.cciss_tape_cmds=8