Re: should an end user stick to a kernel with an initrd?

[Regid Ichira <regid23@nt1.in>]

On Sat, 28 Sep 2013 21:29:35 +0900 Joel Rees wrote:
> On Sat, Sep 28, 2013 at 8:49 PM, Regid Ichira <regid23@nt1.in> wrote:
> > On Fri, 27 Sep 2013 19:06:43 -0400, Tom H wrote:
> >> [...]
> >> As I said, more or less, in a reply to Ralf, can you guarantee that no
> >> other Linux user will have a disk renamed?
> >>
> >
> >   If I understand
> > http://www.debian.org/releases/stable/i386/apcs04.html.en correctly,
> > then yes.  I can guarantee, as long as you don't have udev rules, or
> > other deliberate commands for renaming, including, perhaps by initrd,
> > that no other Linux user will have a disk renamed.  Hotplug devices
> > might differ.  I am not sure if hotplug devices actually require such
> > rules to guarantee stable names.
> 
> Old information. All disks pretend to be SCSI now.
> 
> That's sort of part of the problem, except, even when that page was
> correct, there were conditions not mentioned.
> 
> If one drive spins up slow and comes up to speed out of order, the names change.
> 
> For instance, you have three ATA disks attached in a certain order.
> They would usually be given the spin-up command in the order they are
> attached, and they would usually spin up in the same order.
> 
> If, for some reason, they spin up out of order, your naming changes.
> 

  I am not familiar with the ATA protocol.  Are you saying that the
kernel has no way to know the time on which each disk spined up? 
Doesn't the disk returns a SPINED_UP_AND_WAITING response, together
with its unique address?  
  With scsi, the disk address is determined by its physical
connection to the scsi cable.  On the scsi cable, there is always a
connector that is most closest to the scsi controller.  And a
connector that is next to the closest one, and so on.