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Diffstat (limited to 'Documentation/blockdev/cciss.txt')
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diff --git a/Documentation/blockdev/cciss.txt b/Documentation/blockdev/cciss.txt deleted file mode 100644 index 3a5477cc456e..000000000000 --- a/Documentation/blockdev/cciss.txt +++ /dev/null @@ -1,194 +0,0 @@ -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 -enough (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 |