Subject: Re: "Root on... dumps on..."
To: Zbigniew Baniewski <>
From: Kevin Brunelle <>
List: netbsd-users
Date: 11/04/2006 22:21:32
On Saturday 04 November 2006 21:43, Zbigniew Baniewski wrote:
> The generic kernel reports when booting the system:
> "root on wd0h dumps on wd0b"
> Yes, I'm aware "root" means "root filesystem" - but I'm not sure, what kind
> of dumps is mentioned there? "Core dumps"?
> Couldn't find the config file, which has the place for that "dumps" pointed
> - is it fixed directly in the kernel config file, without the possibility
> to change the "dumps partition" to different place (in the other way, than
> kernel recompilation)?

If and when your system panics (crashes) the entire state of memory with 
be "dumped" onto your swap partition.  This is so that it can be recovered 
with savecore and you can debug the problem.  You do not want to change the 
partition to one which holds valid data as the entire partition would be 
destroyed in the case of a panic.

You can change the place savecore will store these dumps when you reboot 
(defaults to /var/crash).  If this directory does not exist then savecore 
will abort and you won't have to worry about these dumps.

It is for this reason that your swap space should at least equal the physical 
memory of the machine or you will never be able to get a valid crash dump.

As for changing the paritition (like to wd1b ... I am not sure how to do that 
exactly but I know it shoud be able to be done).  But there is little 
practical reason to do that unless that is the only location with a large 
enough swap area.  NEVER change it to a partition with a filesystem on it or 
one that has information you need... because it will be destroyed.