Subject: Re: Root file system mounts read-only
To: None <current-users@NetBSD.org>
From: Alan Barrett <apb@cequrux.com>
List: current-users
Date: 10/12/2007 12:06:45
On Fri, 12 Oct 2007, John Nemeth wrote:
> On Mar 3, 10:18pm, Kenneth Freidank wrote:
> } I newly built NetBSD-4-0-RC2 kernel, but when I loaded it to the target, 
> } the root file system of the target mounted read-only.
> } 
> } ===> Summary of results:
> }          build.sh command: ./build.sh -T /usr/tools -U kernel=IBM1161
> }          build.sh started: Fri Oct 12 01:40:45 EST 2007
> }          NetBSD version:   4.0_RC2
> }          MACHINE:          i386
> }          MACHINE_ARCH:     i386
> }          Build platform:   NetBSD 4.99.31 i386

You were running NetBSD-4.99.31, and you built a kernel for
NetBSD-4.0_RC2.  OK so far, provided you don't attempt to boot that
kernel somewhere where it won't work.

> } I can't give you a dmesg output because I can save anything.  I can't 
> } mount a memory stick either.
> } ibm1161$ mount -t msdos /dev/sd0e /mnt
> } mount: /mnt: Bad system call

Then you actually booted that NetBSD-4.0_RC2 kernel on the build machine
(which has NetBSD-4.99.* userland?)  Or did you boot it on a different
machine?

>      Looks like your userland is out of sync with your kernel.

Yes.  Using a new kernel with old userland usually works (and is
supposed to be supported), but using an old kernel with new userland
is unsupported and seldom works.  The main reason for this is that new
userland assumes that it can use facilities provided by new kernels, but
old kernels don't provide those facilities.

--apb (Alan Barrett)