On Wed, Nov 14, 2007 at 12:26:23PM +0100, Petar Bogdanovic wrote:
> My second question is about the dump-device topic mentioned in the
> NetBSD-Guide:
> 
> 	``The normal swap area in our case is on raid0b but this can not
> 	  be used for crash dumps as process scheduling is stopped when
> 	  dumps happen. Therefore we must use a real disk device. However,
> 	  nothing stops us from defining a dump area which overlaps with
> 	  raid0b.''

Not that this is no longer true for -current, you can dump to raid0b
now.

> If no `overlapping real disk device' is defined on wd[01], I assume
> savecore(8) would eventually fail to do a core-dump but how fatal is
> this on a remote server with no debugging possibilities?

There are two parts of an answer:
 - Crashdumps are very valuable even if you can not debug on the remote
   server that created them. You don't need remote console to use them.
 - If you don't want (or can't create) crashdumps, it will not impact
   your server in any way (as long as it does not crash).

I think worst case scenario is that you get a crash dump written to some
swap partition but savecore will not save it. You can prevent the creation
of the crashdump via "swapctl -D none".

Martin