Re: linux-kernel-digest V1 #104

Alan Cox (iialan@iifeak.swan.ac.uk)
Mon, 3 Jul 1995 10:16:23 +0100 (BST)


Marek Writes:
> I heard that some other systems actually do a crash dump to swap space.
> This might be useful, but of course we should be sure that we are writing
> in the right place... Maybe just check for swap-space signature first?
> A full memory dump might be very helpful in tracking down some problems.

Often the swap data is also needed for the 'complete picture'. Also I have
heard enough horror stories of crash dumps from confused machines writing
to the wrong partition. At the point the machine crashes something is very
wrong. Drew discussed the ideas of a checksummed crash dumper in Germany,
that might be safe.

> From: Jim Nance <jlnance@isscad.com>
> This is in response to a message about caching NFS file to disk that was
> posted here a few days ago. Of course I deleted the message and then
> decided to reply to it :-(. The basic idea was to cache NFS files to a local
> disk since NFS is slow. I have also seen a suggestion to do the same for
> CDROMS since they are also slow.

This would be a big gain for paging. Having a non page flag so that binaries
off CD-ROM page back/forth from swap would need more swap but avoid the
penalties of slow CD-ROM seeks.