* SA 6400
* SA 6400 U320 Expansion Module
* SA 6i
- * SA 6422
- * SA V100
+ * SA P600
+ * SA P800
+ * SA E400
+ * SA P400i
+ * SA E200
+ * SA E200i
+ * SA E500
-If nodes are not already created in the /dev/cciss directory
+If nodes are not already created in the /dev/cciss directory, run as root:
-# mkdev.cciss [ctlrs]
-
-Where ctlrs is the number of controllers you have (defaults to 1 if not
-specified).
+# cd /dev
+# ./MAKEDEV cciss
Device Naming:
--------------
-You need some entries in /dev for the cciss device. The mkdev.cciss script
+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
- etc...
+ 106 cciss2
+ 105 cciss3
+ 108 cciss4
+ 109 cciss5
+ 110 cciss6
+ 111 cciss7
Minor numbers:
b7 b6 b5 b4 b3 b2 b1 b0
|
+-------------------- Logical Volume number
-The suggested device naming scheme is:
+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
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).
+(typically in /etc/init.d, but could vary depending on distribution).
For example:
for x in /proc/driver/cciss/cciss[0-9]*
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.) This is because
-of changes to the 2.4 kernel PCI interface related to PCI hot plug
-that imply the driver must register with the SCSI mid layer once per
-adapter instance rather than once per driver.
+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 OS from attempting to directly
+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.
+
git://git.onelab.eu / linux-2.6.git / blobdiff