Subject: Re: "Root on... dumps on..."
To: Malcolm Herbert <firstname.lastname@example.org>
From: Kevin Brunelle <email@example.com>
Date: 11/05/2006 01:05:08
On Sunday 05 November 2006 00:17, Malcolm Herbert wrote:
> How does this behave in cases where we are using RAIDFrame? I'm using it
> for my root disk and booting from it directly ... if the kernel needs to
> create such a dump, how will this interact with RAIDFrame when it tries
> to dump to /dev/raid0b as advertised?
You should not do that.
Here's a good article explaining what to do
http://users.piuha.net/martti/comp/raid/raid.html but I will try and cover
the relevant parts. Note, I don't currently have this setup myself but I am
looking into it for someone.
/dev/raid0a / ffs rw 1 1
/dev/raid0b none swap sw 0 0
/dev/raid0e /home ffs rw 1 1
/dev/wd0b none swap dp 0 0
In this case, /dev/wd0b is aligned with the part of /dev/raid0b that is on
wd0... you'll have to read the article to get a full understanding.
Basically, this way the kernel knows the actual disk areas where to dump the
information. You need to use swapoff to avoid parity errors and such.
In practice I am not sure how well all this works or what effect it has on
swapping. But if you're concerned about this and you are unlikely to ever
use a dump... just turn off dumps entirely.
Add the following line to /etc/sysctl.conf
I hope you're less confused than I am after writing that. Basically, don't
dump to raid0b... either use the solution from that link or turn dumping off.