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authorMike Miller <mike.miller@hp.com>2008-08-04 05:54:53 -0400
committerJens Axboe <jens.axboe@oracle.com>2008-08-06 06:30:04 -0400
commitf4a93bcda74edfe6977dcf296ed8c86119638871 (patch)
tree866f59740b737e23254160dea1bdc527292c76ce /Documentation
parenteece695f8bf9d1aacf3a119ab8e21db31948e40b (diff)
cciss: change the way we notify scsi midlayer of tape drives
This patch changes way we notify the scsi layer that something has changed on the SCSI tape side of the driver. The user can now just tell the driver to rescan a particular controller rather than having to know the SCSI nexus to echo into the SCSI mid-layer. Signed-off-by: Stephen M. Cameron <scameron@beardog.cca.cpqcorp.net> Signed-off-by: Mike Miller <mike.miller@hp.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/cciss.txt21
1 files changed, 6 insertions, 15 deletions
diff --git a/Documentation/cciss.txt b/Documentation/cciss.txt
index 63e59b8847c5..8244c6442faa 100644
--- a/Documentation/cciss.txt
+++ b/Documentation/cciss.txt
@@ -112,27 +112,18 @@ Hot plug support for SCSI tape drives
112 112
113Hot plugging of SCSI tape drives is supported, with some caveats. 113Hot plugging of SCSI tape drives is supported, with some caveats.
114The cciss driver must be informed that changes to the SCSI bus 114The cciss driver must be informed that changes to the SCSI bus
115have been made, in addition to and prior to informing the SCSI 115have been made. This may be done via the /proc filesystem.
116mid layer. This may be done via the /proc filesystem. For example: 116For example:
117 117
118 echo "rescan" > /proc/scsi/cciss0/1 118 echo "rescan" > /proc/scsi/cciss0/1
119 119
120This causes the adapter to query the adapter about changes to the 120This causes the driver to query the adapter about changes to the
121physical SCSI buses and/or fibre channel arbitrated loop and the 121physical SCSI buses and/or fibre channel arbitrated loop and the
122driver to make note of any new or removed sequential access devices 122driver to make note of any new or removed sequential access devices
123or medium changers. The driver will output messages indicating what 123or medium changers. The driver will output messages indicating what
124devices have been added or removed and the controller, bus, target and 124devices have been added or removed and the controller, bus, target and
125lun used to address the device. Once this is done, the SCSI mid layer 125lun used to address the device. It then notifies the SCSI mid layer
126can be informed of changes to the virtual SCSI bus which the driver 126of these changes.
127presents to it in the usual way. For example:
128
129 echo scsi add-single-device 3 2 1 0 > /proc/scsi/scsi
130
131to add a device on controller 3, bus 2, target 1, lun 0. Note that
132the driver makes an effort to preserve the devices positions
133in the virtual SCSI bus, so if you are only moving tape drives
134around on the same adapter and not adding or removing tape drives
135from the adapter, informing the SCSI mid layer may not be necessary.
136 127
137Note that the naming convention of the /proc filesystem entries 128Note that the naming convention of the /proc filesystem entries
138contains a number in addition to the driver name. (E.g. "cciss0" 129contains a number in addition to the driver name. (E.g. "cciss0"