booting single user mode

Aiza aiza21 at
Mon Feb 22 04:04:24 UTC 2010

Jerry McAllister wrote:
> On Mon, Feb 22, 2010 at 10:39:57AM +0800, Aiza wrote:
>> Looking for conformation.
>> On booting into single user mode all files systems are unmounted except 
>> / which is mounted read only.
>> Is this true?
>> Will dump/restore commands work?
> Generally yes.   Make sure they are in your path and available to you
> in whatever filesystem[s] you have mounted.  I think they normally are.
> I believe dump and restore are in  /sbin  which should be part of your
> root filesystem and not in its own partition.   ==Never put those things
> that should be in root in their own partitions==
> To check where they are use 'which'   which dump   or  which restore
> will tell you where they are.
> When you dump a non mounted filesystem, I think you have to use
> the partition name, not the mount name.   
> So, instead of
>   dump 0afL /dev/nsa0 /usr     
> it might be
>   dump 0afL /dev/nsa0 /dev/ad0s1d
> if your mount a partition /dev/ad0s1d as /usr normaly.
> You don't really need to restore to an unmounted partition, though
> using single user might be useful.   If you are restoring in single
> user, do something like this.
>   fsck -a
>   mount -u /
>   mount -a
>   cd /usr
>   restore -rf /dev/nsa0
> Note: I am using /dev/nsa0 as where the dump media is.  that would
>       be a tape device.  You need to adjust this for where you really
>       write the dump or have the dump stored.
> ////jerry

Think mistake here   dump 0afL /dev/nsa0 /usr
Whole reason for doing dump in single user mode is no snapshot so no 
need for -L flag in your example dump command.

More information about the freebsd-questions mailing list