On Tue, Feb 06, 2001 at 11:04:46PM -0800, Chuck McManis wrote:
> At 01:31 AM 2/7/01 -0500, Lord Isildur wrote:
> > > DSSI also has hot swap capability. Do you want ra2 to vanish and re-appear
> > > as ra6?
> >
> >yes, if it's now on id 6.
> 
> Currently the disk subsystem doesn't work that way. MSCP disks are numbered 
> sequentially from 0 in the order in which they are probed. So for example 
> on the CQD220 controller disk target 0 and disk target 3 become ra0 and 
> ra1, then disk 1 on the second controller becomes ra2, etc. If you remove a 
> drive and re-add it then it would change its disk number which has no 
> relation to its 'id.'

This is why our configuration framework allows device instances to be 
hardwired to specific unit numbers, along with various other features which
if used correctly pretty much eliminate this problem.