Re: Mounting a dump file

[Ray Phillips <r.phillips%uq.edu.au@localhost>]

> Don't try to mount(8) the output from dump(8) - that output is a 
> file, and not a filesystem!

Thanks for setting me straight on that; something I should have realised.  :(

> When you are actually ready to extract everything, use "restore -r -f ..."

OK, I didn't know about restore(8)'s -r option.  In the instructions 
I've been following for setting up a machine with the root file 
system on a RAID1 partition:

http://lsi.vc.ehu.es/pablogn/docencia/manuales/configuraciones/raid/raid.html#7

it says to copy the files from the non-RAID partition to the RAID one 
like this:

# mount /dev/raid0a /mnt
# dump -0 -f - / | (cd /mnt && restore -x -f -)

Would it be better to use the  -r  option for restore(8) here instead 
of -x  or is there no practical difference?

I've now restored the contents of a dump file and it reported a problem:

# restore -r -f dump-file
./var/db/dhcpd.leases~: not found on tape

even though that file was present after restore(8) had finished. 
What might lead to that confusion?


This is a bit of a digression from the current topic but perhaps you 
wouldn't ming explaining what's happening...

Curiously, even though the dump file contained a NetBSD 5.1.2 system, 
when I booted the restored system and logged in it said:


NetBSD 6.0.1 (GENERIC)

Welcome to NetBSD!


and /etc/motd confirmed it was version 6.0.1:

% cat /etc/motd
NetBSD 6.0.1 (GENERIC)

Welcome to NetBSD!

%

as did `uname -r' but the rest of the system seemed to be a faithful 
copy of the original.

The machine I've been doing this on is a Dell Precision 410 with the 
RAID1 array on two SCSI disks.  The  dump file I restored from is on 
an IDE disk which also has NetBSD i386 6.0.1 installed on it.  I 
finally realised that with the IDE disk connected when booting the 
restored 5.1.2 system, /etc/motd gets overwritten with 6.0.1's 
version during booting into multi-user mode and the 6.0.1 kernel is 
used, even though the boot sequence messages say:

boot device: raid0
root on raid0a dumps on raid0b

So I created a rod for my own back by putting a system the IDE disk. 
/etc/motd reverts to the 5.1.2 version when the IDE disk isn't 
attached though, which surprised me too.  What's going on in the 
background when the `Updating motd' message appears when the machine 
is booting?


Ray