Date: Fri, 7 Apr 2006 16:01:52 -0700 (PDT) From: Paul Marciano <pm940@yahoo.com> To: Peter Wemm <peter@wemm.org>, freebsd-questions@freebsd.org Cc: Paul Marciano <pm940@yahoo.com> Subject: Re: Does FreeBSD support sparse kernel crash dumps? Message-ID: <20060407230152.57316.qmail@web54004.mail.yahoo.com> In-Reply-To: <200604071520.03764.peter@wemm.org>
next in thread | previous in thread | raw e-mail | index | archive | help
--- Peter Wemm <peter@wemm.org> wrote: > On Friday 07 April 2006 12:47 pm, Paul Marciano > wrote: > > Hello. I read a while back about someone working > on > > supporting sparse kernel crash dumps (dumping only > the > > active kernel pages to the dump device as opposed > to > > all physical memory - for machines where the phys > mem > > is greater than the dump dev space.) > > > > Does anyone know the status of that project? Was > it > > committed, or are there plans to commit it? > > I have a working prototype as of last night. There > should be something > committable in the next week or two. > > When I boot my 2GB machine and force a crash dump > from single user mode, the > fully debuggable vmcore file is in the 40-50MB > range. A busy machine with > 12GB ram took about 150MB to dump. > > There are still some things to work out. It was > written for the amd64 kernel, > but can be ported to i386. > > -Peter > That's very timely news Peter. Do you think your code is easily back-portable to 5.4? Are the changes limited to dump_machdep.c or otherwise not dependent on a great deal of -current updates? Do you compress the data stream at all (e.g. gzip)? I have a specific need on a CompactFlash based system. I have a 256MB IDE mode card on a machine with 512MB physical memory. I can probably commit 128MB of the card as a dumpdev but I can't go beyond that. Good luck with it. Regards, Paul. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20060407230152.57316.qmail>