Subject: Re: Dumping to wedges
To: Martin Husemann <firstname.lastname@example.org>
From: Jason Thorpe <email@example.com>
Date: 08/15/2006 10:07:14
On Aug 14, 2006, at 6:07 PM, Martin Husemann wrote:
> On Mon, Aug 14, 2006 at 10:12:18PM +0200, Martin Husemann wrote:
>> Besides wedges not autoconfiguring the dump device (which is pretty
>> easy to
>> solve and testable w/o writing a dump all over your disk ;-})
> Here is a complete patch, including the autoconfig parts.
> I haven't tried writing a kernel dump with it yet.
I don't really like the autoconfig parts. I would rather not export
the notion of "finding swap" from the wedge code itself. Honestly,
I'm not sure I see the value in auto-configuring the dump device
anymore. Let it be configured during early system start-up. I think
we should remove all that code completely from the kernel.
As far as writing the dump is concerned:
1- The lockmgr stuff is going to be interesting -- what if the kernel
panic'd while the lock was held, etc. I guess this is a general
problem with crash dumps anyway -- an awful lot of the kernel needs to
work in order to be able to use them.
2- Yes, you do need to open the device, because you need to make an
open call to the backing device (it might need to spin up the media,