Subject: Dynamic disk naming
To: None <netbsd-users@NetBSD.ORG>
From: Ed Symanzik <>
List: netbsd-users
Date: 03/17/1995 23:25:32
  The dynamic disk naming (first disk found is sd0, second is sd1) is a 
nice thought but it causes more trouble than it solves.  Right now my 
boot disk is SCSI ID 1.  If I add a disk at ID 0, I can't boot because 
fstab is suddenly pointing to the wrong disk.  In fact, that's probably 
a security hole.

  If disks move, the system needs to continue mounting the same disks 
in the same places.  To do so, the system needs to put some identifying
mark on each disk and make a note of it somewhere on the boot disk.
For instance, drive A is sd0 and drive B is sd1.  Now, if I add another
drive, it gets sd2 and I can still boot from drive A and mount drive B.
Also, I can change the SCSI ID of my boot disk and still have a working 

Ed Symanzik
Michigan State University