Why not just name the cam-ata devices the same as the old names?

[Jeremy Chadwick]

On Wed, Apr 27, 2011 at 10:44:58AM +0400, Pan Tsu wrote:
> "Jason J. Hellenthal" <jhell at DataIX.net> writes:
> 
> > I do not know if this was summed up in a easy way by Jeremy's nice
> > message below but in short a summary can be made here to clear that up.
> >
> > /dev/gptid/* /dev/gpt/*
> > 	* These survive its raw partition being newfs'd
> > 	* Are only created for disks that are partitioned
> > 	  and contain a GPT table as can be seen with gpart
> > 	  show
> > 	* Operations on these or the raw partition will not remove them.
> 
> Not sure if we have support for labels based on disk serial number
> similar to /dev/serno/* from DragonFlyBSD but
> 
> /dev/serno/*
> 	* no extra step to setup, e.g. `gpart create' or `newfs'
> 	* survive wiping entire disk, no metadata stored on-disk
> 	* available on every ata disk

How is this number generated within DFBSD?  I have seen hard disks that
have literally no serial number (field is blank, and not space-padded
either).  Some systems vendors do this.  I'm wondering if the generated
number is based on a combination of details (ex. device model string +
serial number string + total drive capacity in bytes), rather than just
pure drive serial number.

CC'ing Matt as he probably knows.  :-)

-- 
| Jeremy Chadwick                                   jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.               PGP 4BD6C0CB |