Fw: Re: Disk partitions cannot be found/mounted after swappi

Duncan Barclay dmlb at dmlb.org
Tue Oct 15 20:18:36 BST 2002

On 15-Oct-2002 David Marsh wrote:
> [oops, I meant to send this to the list, and didn't notice the reply
> address]
> On Tue, 15 Oct 2002 14:25:15 +0100
> Pete French <pete at twisted.org.uk> wrote:
>> > Given that /dev/ad1s2a (/) is only mounted read-only at this point
>> > [and I'm kinda confused as to how the kernel is happy to have it
>> > mounted like so one second, and then deny its existence the
>> > next!??], how can I make the partition mountable in writable mode so
>> > that I can update the device nodes?
>> can you boot up single user 
> That's "boot -s" at the boot prompt? (I'm a bit rusty on this..)
>> and then do 'mount -rw /' ? that works
>> for me to get / read/write
> No joy, unfortunately. :-(
> mount replies:
> mount: /dev/ad1s2a: No such file or directory

I've hit this problem and cheated in the past by pulling the drive out
and onto another machine where I can mount / rw, and then makedev it.

The elgant solution that I thought of is to somehow make a RAM disk
with mount_mfs and mknod the required device entry in the mfs. Mount /
on that r/w, and then create the real entry in /dev.

This is from the top of my head. If someone can try it out and make it a script
maybe we can put it in /sbin. Call it paddle or canoe or even wetsuit
(up s**t creek etc.)

        boot -s

        mount_mfs -T minimum -s 131072 /dev/null /tmp
        cd /tmp
        cp /dev/MAKEDEV .
        ./MAKEDEV ad1s2a
        mount /tmp/ad1s2a /mnt
        cd /mnt/dev
        ./MAKEDEV ad1s2a

Untested apart from the mount_mfs line (/dev/null is not used as the
special device, the -T minimum supplies parameters for newfs).


Duncan Barclay  | God smiles upon the little children,
dmlb at dmlb.org   | the alcoholics, and the permanently stoned.
dmlb at freebsd.org| Steven King

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