Re: disk naming proposal & devfs

Kevin Lentin (kevinl@cs.monash.edu.au)
Mon, 12 Jan 1998 16:41:49 +1100


On Mon, Jan 12, 1998 at 08:26:46AM +1100, Richard Gooch wrote:
> > The point is to be able to have the different partitions be //location
> > idependent//. So if a disk is added, or moved from controller to
> > controller, then the system can come up without needing to ask any
> > questions or having /etc/fstab changed. fstab can look something like
> >
> > /dev/root / ext2 defaults 1 1
> > /dev/usr /usr ext2 defaults 1 2
>
> I don't see how this could possibly work. If I haven't yet mounted
> /usr, how can the system know what /dev/usr is (in your naming
> scheme)?

I suppose we'd be talking about a proprietory partitioning scheme - or
finding somewhere else on the disk to store the names. The kernel finds the
names at boot time during the partition probe and presents them in /dev.

> Er, hold on. I think I see more what you're trying to do. You want to
> move /etc/fstab elsewhere, essentially. So each FS/partition will
> record where it should be mounted?

A partition should have a NAME associated with it that is stored either at
the start of the partition or in or related to the partition table. Those
names present themselves (through devfs) in /dev and fstab tells it where
to mount. One person might call the partitions 'root' and 'usr'. On my home
system I might call them 'scsiroot', 'scsismall', 'scsibig', 'idebig',
'ideswap'. But I owuld mount them on /root, /tmp, /u/stuff, /u/work and
swap.

BUT I could pull the disk out, bring it over to your place, plug it in and
know what names the partitions would have.

All you need is a clash solution. You could use date last mounted or other
heuristics and call them root~1 and root~2 (just to piss off the Win95
haters amongst us :-)

-- 
[======================================================================]
[     Kevin Lentin               Email: K.Lentin@cs.monash.edu.au      ]
[   finger kevinl@fangorn.cs.monash.edu.au for PGP public key block.   ]
[  KeyId: 06808EED    FingerPrint: 6024308DE1F84314  811B511DBA6FD596  ]
[======================================================================]