Re: SCSI disk devices

Manish Vachharajani (mvachhar@pythagoras.rutgers.edu)
Thu, 1 May 1997 16:51:22 -0400


Date: Thu, 1 May 1997 06:15:40 -0400
From: Eric Youngdale <eric@andante.jic.com>

I am not 100% sure what the best long term solution is. Some
people have suggested that a /proc/scsi/dev/ tree be populated with
names and links that are somewhat representative of whatever the ID,
etc, are for the underlying device. I don't know what the performance
impact would be of doing something like this, but on the surface it
doesn't seem unreasonable. I guess my reaction is that I would prefer
the solution live outside of the kernel (and hence scsidev), as it is
more configurable and adaptable.

At the very least though, I think the kernel should allocate minor
scsi device numbers based on controller number and id. This way the
things will change in a predictable manner(Though I guess numbering
sequentially based on existing devices is predicatable as well, just
not convenient.)

This would be very useful in conjunction with a cxtxsxdx naming
scheme. I can then add a disk with an id of say 1, when my root disk
id is 3 and not get an unbootable system unless I do a root=/dev/sdx.
I am not sure how to deal with LUN's on devices in this scheme though.

-- 
Manish Vachharajani 		            <mvachhar@noc.rutgers.edu>
Rutgers University 		   http://www-no.rutgers.edu/~mvachhar	
Telecommunications Division 
Systems Programmer