freebsd8.2 with /etc mount point can't run correctly

[Trond Endrestøl]

On Tue, 28 May 2013 13:29+0430, saeedeh motlagh wrote:

> On Tue, May 28, 2013 at 1:16 PM, Trond Endrestøl <
> Trond.Endrestol at fagskolen.gjovik.no> wrote:
> 
> > On Tue, 28 May 2013 12:57+0430, s m wrote:
> >
> > > hello all,
> > >
> > > i want to install freebsd8.2 with different partitions. i want to have
> > > a separated partition for /etc. therefore this is my partitions: / ,
> > > /var, /etc. /tmp, /usr, swap.
> > >
> > > but after installing, freebsd can not run correctly and have problem
> > > with fstab. i checked my fstab file (fstab file in /etc partition) and
> > > every thing is ok. i think i should do something in order to use fstab
> > > file in different mount point. is it true? what should i do to have a
> > > freebsd with a separate /etc mount point?
> > >
> > > any comments are appreciated.
> > > SAM
> >
> > If you really want to keep /etc as a separate filesystem, then I would
> > try something like this:
> >
> > 1. Create the file /etc-mount and give it the following contents:
> >
> > #!/bin/sh
> > /sbin/mount /dev/ada0pX /etc
> > exec /etc/rc $*
> >
> > 2. Make sure to substitute the right device file for the mount
> > command.
> >
> > 2. Make /etc-mount executable: chmod a+x /etc-mount
> >
> > 3. On the root filesystem, let /etc/rc be a symlink to /etc-mount.
> >
> > This is just off the top of my head. It may work, or it may not work.
> >
> > HTH.

> thanks Trond but i think it can not help me.
> 
> you know i want to separate my /etc completely from root. for some reasons,
> i want to unmount /etc while root is mounted.
> 
> by your procedure, i think /etc is dependent to root yet. isn't it?

When the system boots, init(8) fires up a shell to execute the 
commands contained in (the real) /etc/rc. At boot only the root file 
system is mounted, thus you need a mechanism to mount /etc ahead of 
normal startup and pass whatever arguments the fake /etc/rc was 
invoked with on to the real /etc/rc.

As long as no processes holds open any files within /etc and you don't 
need any of the files, /etc/{,s}pwd.db og /etc/group comes to mind, 
you should be able to unmount /etc at your own pace. I guess you 
should be in single user mode while doing this.

Why do you need this strange detachment anyway?
Backups? Snapshots?

-- 
+-------------------------------+------------------------------------+
| Vennlig hilsen,               | Best regards,                      |
| Trond Endrestøl,              | Trond Endrestøl,                   |
| IT-ansvarlig,                 | System administrator,              |
| Fagskolen Innlandet,          | Gjøvik Technical College, Norway,  |
| tlf. mob.   952 62 567,       | Cellular...: +47 952 62 567,       |
| sentralbord 61 14 54 00.      | Switchboard: +47 61 14 54 00.      |
+-------------------------------+------------------------------------+