Re: [lkcd-general] Re: What's left over.

[linux@horizon.com]

Just to complicate things, consider this setup:

# cat /proc/swaps
Filename			Type		Size	Used	Priority
/dev/md5                        partition	999864	16904	0
/dev/md6                        partition	999864	16924	0
/dev/md7                        partition	999864	16920	0

Those are all RAID-1 mirrors, a measure whose ass-saving value I have
enjoyed.

While a crash dump to just half of one of those mirrors is fine, finding it
might be a little bit tricky.  And the fact that the kernel reassembles
the mirrors automatically on boot might make retrieving the data a little
bit tricky, too.

(After a crash, the mirrors will be inconsistent, so one will get copied
over the other, but I'm not too clear on which direction it'll happen in.)

I can't NOT reassemble at least some mirrors on boot because / is mirrored!

Now, to that, add the case that each of those is significantly smaller than
main memory.  (2/3 size would still allow swap = 2*ram.)


The problem is that hardware is getting more and more sopisticated and
requiring ever more elaborate device drivers.  Eventually you have to
have a cutoff and say that something is too complex to talk to after a
crash, even though it's theoretically available.  Where is that line?
USB?  iSCSI?  This situation?

A reasonable fallback is to just drop in a cheap crappy dedicated
IDE drive for catching crash dumps, but I'd like the crash dumper to
know how to wake it up from sleep mode; I'd hate to leave it spinning
all the time...