autoloading sg driver during boot

[Aleksandar Milivojevic]

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)".

-- 
Aleksandar Milivojevic <amilivojevic at pbl.ca>    Pollard Banknote Limited
Systems Administrator                           1499 Buffalo Place
Tel: (204) 474-2323 ext 276                     Winnipeg, MB  R3T 1L7