autoloading sg driver during boot

[Paul Howarth]

Aleksandar Milivojevic wrote:
> Paul Howarth wrote:
> 
>> I have a SCSI scanner that uses the sg module; I wrote a custom udev
>> rule to identify the scanner when the SCSI adapter module detects it,
>> and that then creates the /dev/sg* entry for it. Can't you do something
>> like that?
> 
> 
> I did some quick reading of udev documentation yesterday.  However, I 
> don't see how to exactly do it.  A symlink for tape isn't going to work 
> (/dev/st0 and /dev/sg1 use different set of IOCTLs, "mt -f /dev/sg1 
> rewind" is going to give an error for example).  For the medium changer, 
> kernel doesn't create any special device (there's no special driver for 
> it, such as st for tapes or sd_mod for disks), the only way of accessing 
> it is through /dev/sg0.
> 
> Unless I missed something obvious in documentation, and there is a way 
> to tell udev "when kernel detects a device controlled by st module (char 
> major 9), also create device nodes for sg module (char major 21)".

Aren't the tape and the autochanger using different SCSI IDs or LUNs?

Try this:
Manually load the sg module so that the sg devices get created.
What do you then get for:
$ udevinfo -a -p `udevinfo -q path -n /dev/sg0`
and
$ udevinfo -a -p `udevinfo -q path -n /dev/sg1`

Paul.