Re: dump to cgdNb device

[Taylor R Campbell <campbell+netbsd-tech-kern%mumble.net@localhost>]

   Date: Thu, 16 Jun 2016 21:48:18 +0100
   From: Alexander Nasonov <alnsn%yandex.ru@localhost>

   Taylor R Campbell wrote:
   > So maybe it did get written, but there's just something funny about
   > it.  If you pass -v to savecore, can you find what aspect of the dump
   > savecore doesn't like?

   I don't see any difference between -vf and -f.

   savecore: magic number mismatch (0x0 != 0x8fca0101)

Can you ktrace it to see what devices it's actually looking at?

Every time I try to scrutinize savecore it makes me dizzy.  I think if
you selected cgd1b as the dump device with `swapctl -D', rather than
using the default of <rootdev>b, and/or if the running kernel image
doesn't match the dumped kernel image, savecore may get confused.

Maybe savecore should have an option to specify what the dump device
is supposed to be.