Re: Some quick scsi documentation questions:

[Stefan Richter <stefanr@s5r6.in-berlin.de>]

> Rob Landley wrote:
>> So if you don't attach an sg to every sd, then either there are holes, or they 
>> don't line up, in which case how do you tell which sg goes with a given sd?

Sysfs has pointers from a SCSI logical unit device to the corresponding
sd device and sg device...

$ ll /sys/bus/scsi/devices/1\:0\:0\:0/[bg]*
lrwxrwxrwx 1 root root 0 Aug  2 23:23
/sys/bus/scsi/devices/1:0:0:0/block:sdb -> ../../../../../../block/sdb
lrwxrwxrwx 1 root root 0 Aug  2 23:23
/sys/bus/scsi/devices/1:0:0:0/generic ->
../../../../../../class/scsi_generic/sg1


...as well as from the sd and sg devices to the corresponding SCSI
logical unit device:

$ ll /sys/block/sdb/device
lrwxrwxrwx 1 root root 0 Aug  2 23:27 /sys/block/sdb/device ->
../../devices/pci0000:00/0000:00:1f.2/host1/target1:0:0/1:0:0:0

$ ll /sys/class/scsi_generic/sg1/device
lrwxrwxrwx 1 root root 0 Aug  2 23:24 /sys/class/scsi_generic/sg1/device
-> ../../../devices/pci0000:00/0000:00:1f.2/host1/target1:0:0/1:0:0:0


The place where these symlinks live might change in the future.  See
linux-2.6.23*/Documentation/sysfs-rules.txt.
-- 
Stefan Richter
-=====-=-=== =--- ---=-
http://arcgraph.de/sr/