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Diffstat (limited to 'Documentation/cciss.txt')
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diff --git a/Documentation/cciss.txt b/Documentation/cciss.txt new file mode 100644 index 000000000000..d599beb9df8a --- /dev/null +++ b/Documentation/cciss.txt @@ -0,0 +1,132 @@ +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 + +If nodes are not already created in the /dev/cciss directory, run as root: + +# cd /dev +# ./MAKEDEV cciss + +Device Naming: +-------------- + +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 + +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 not engage the SCSI core at init +time. The driver must 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 because at driver init time, +the SCSI core may not yet be initialized (because the driver is a block +driver) and attempting to register it with the SCSI core in such a case +would cause a hang. This is best done via an initialization script +(typically in /etc/init.d, but could vary depending on distibution). +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, in addition to and prior to informing the SCSI +mid layer. This may be done via the /proc filesystem. For example: + + echo "rescan" > /proc/scsi/cciss0/1 + +This causes the adapter 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. Once this is done, the SCSI mid layer +can be informed of changes to the virtual SCSI bus which the driver +presents to it in the usual way. For example: + + echo scsi add-single-device 3 2 1 0 > /proc/scsi/scsi + +to add a device on controller 3, bus 2, target 1, lun 0. Note that +the driver makes an effort to preserve the devices positions +in the virtual SCSI bus, so if you are only moving tape drives +around on the same adapter and not adding or removing tape drives +from the adapter, informing the SCSI mid layer may not be necessary. + +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. + |