Re: devfs

[Jeff Garzik]

Alan Cox wrote:
> 
> > * You know exactly what devices you have.  Under Solaris, a "boot -r"
> >   neatly creates the SCSI devices present, named precisely for their
> >   controller/SCSI/LUN id.  Management couldn't be easier.
> 
> That doesn't need kernel help

If a user-level program will make sure my /dev entries are accurate on
boot-up, great!  Is that possible?

> >   Putting devices in "scan order" never made sense to me.  Why should
> >   the first SCSI drive scanned be /dev/sda?  What happens when I switch
> >   the cables and drives around.  Same filesystems, but the devices have
> >   all changed.
> 
> And this doesnt need kernel help either. In fact using device scan order is
> often more convenient than device position. When it comes to volume management
> of a big system both of these (and Solaris) are equally dumb approaches.

Convenient for whom?  Kernel programmers or admins/users?

What would you suggest as a smart approach to volume management?

> It all comes down to
> 
> 	mount `wherehasitgone --uuid=blah` /mnt/mydisk
> 
> And wherehasitgone is a tool to walk the disk tree and find a volume by uuid
> and/or maybe ask LDAP/NIS maps to find it via NFS

What would this look like in /etc/fstab?

Thanks,

	Jeff

P.S.  I'm not arguing for devfs per se; simply arguing for a "canonical,
never-out-of-date /dev" and "devices named by SCSI id".

-- 
Jeff Garzik			    Typhoon, Cyclone, Diablo, and INN
http://www.spinne.com/usenet/	           News tuning and consulting