Re: [gentoo-dev] Further observations on moving root

["Christian HOFFMANN" <hoffmann@noos.fr>]

Hello,

I recently moved my root partition from one disk to the other and 
experienced the same problem with /dev.

My solution is actualy simple, i did a mount /dev/hda3 /mnt/gentoo 
(hda3 being my old root partition) and moved the hard drive content 
with a tar cf | tar xfp from /mnt/gentoo to the new root. Working that 
way, I copied the actual hard drive file not the dynamic filesystems in 
/dev and /proc.

I worked without any problem, I'm also using this trick to backup my 
system in a way similar of what is described in D.Robbins tutorial on 
devlopperworks.

Regards

> On Wed, 2002-03-20 at 06:15, Fuper wrote:
> > If you ever might add a new disk drive and want to move the Gentoo
> > root partition onto the new (maybe faster) drive then my struggles
> > in doing that may be relevant to you.  Copying the partition didn't
> > just work --- I found that the /dev directory initialization was not
> > obvious.
> > 
> > I did conclude to my own satisfaction that the /sbin/rc script (v. 1.16) 
> > is in error at line 312 and should read as follows:
> >    309  #we want devfsd running after a change of runlevel (if we return
> >    310  #from runlevel 'single')
> >    311  if [ -z "$(ps -A | grep devfsd)" ] && \
> >    312     [ -n "$(cat /proc/mounts | grep -e '/dev devfs')" ]
> >    313  then
> >    314          /sbin/devfsd /dev &>/dev/null
> >    315  fi
> > The distributed script had "cat mounts" and failed when devfsd
> > was not already running.
> > 
> > After reading the devfs FAQ and Robbins paper on devfs at 
> > IBM:developerWorks I concluded that a cleanly built root
> > partition should have an empty /dev directory.  It is entirely
> > populated by devfs when that is "mounted" and accessed.
> > 
> > BUT Gentoo linux, installed from build rc6 r14, crashes when
> > booted from the same /boot partition but using a new root ("/")
> > and an empty /dev (it had more interesting problems when 
> > I attempted to create a fully populated dev/ by copying the
> > in-use /dev from the old root partition onto the new partition
> > s.a.
> >    star -c /dev | star -x -C /mnt/partition  # Don't do this
> > 
> > I had to add the devfs mount option to the kernel so that
> > the grub commands that had been
> >   root (hd0,0)
> >   kernel /boot/bzImage root=/dev/hda2 hdc=ide-scsi
> > became now
> >   root (hd0,0)
> >   kernel /boot/bzImage root=/dev/sdb1 hdc=ide-scsi devfs=mount
> > 
> > It is a mystery to me why it now becomes necessary to add
> > the devfs=mount option to the grub kernel command, booting
> > the same kernel using the same devfs.conf file and same 
> > root partition (but copied onto a new disk).  If this is obvious
> > to everyone else, then so be it; but maybe it is worth 
> > documenting that under some conditions it becomes
> > necessary to add the kernel option.
> > 
> 
> This is because /sbin/init needs /dev/initctl, and as we dropped
> the initwrapper that created that if not existing, it fails when
> a unmounted /dev do not contain it.
> 
> > I hope that this is helpful.
> > _______________________________________________
> > gentoo-dev mailing list
> > gentoo-dev@gentoo.org
> > http://lists.gentoo.org/mailman/listinfo/gentoo-dev
> -- 
> 
> Martin Schlemmer
> Gentoo Linux Developer, Desktop Team Developer
> Cape Town, South Africa
> 
> 
> _______________________________________________
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> gentoo-dev@gentoo.org
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> 

-------------------------------------------
Christian HOFFMANN <hoffmann@noos.fr>