Re: Saving kernel crash dumps

On Mon, 29 Sep 2025 20:03:35 +0200
Martin Husemann <[email protected]> wrote:

> On Mon, Sep 29, 2025 at 06:19:12PM +0100, Sad Clouds wrote:
> > How does NetBSD on sparc64 save crash dumps? Does it require swap
> > space? If yes, does it need to be bigger than the system RAM size? Also
> > how does it know to which device to save crash dumps and is there a way
> > to configure it during boot or via ddb prompt?
> 
> It is saved to the dumpdevice. You can configure it with swapctl
> and it defaults to the swapdevice.
> 
> It needs to be bigger than the memory size.
> 
> Martin

Hello, this is sun4v so the panic occurs during kernel load and before
the system is up and running. I manually extracted sparc64 sets and ran
installboot on sun4u system, then attempted to boot it on sun4v.

I can go back and create a swap partition. But I'm not sure how the
kernel knows about dumpdevice if it did even get a chance to read fstab
file. Are there any boot arguments or openboot variables that need to
be specified?

Thanks.