[cgl_discussion] [Fwd: [Dcl_tech_board] Linux Kernel Crash Dump (LKCD) evaluation]

Peter Badovinatz tabmowzo at us.ibm.com
Mon Apr 14 13:53:56 PDT 2003

John Cherry wrote:
> Steve Hemminger (of DCL fame) wrote up a nice synopsis of the Linux
> Kernel Crash Dump (LKCD) project and where it is going.  There are a
> number of reasons that LKCD is not gaining mainline acceptance
> (dependency on kexec, arch specific, too invasive, bloat, etc.).  Linus
> has stated that he would consider a network-only crash dump, but that is
> not where LKCD is heading.

No argument about lack of LKCD acceptance.  But, maybe this isn't the
place to discuss this, if it's Linus' ear we want, but...  to quote Dave
Anderson of RH (bottom of the original post, which I've snipped to save

> > While Red Hat advocates Ingo's netdump option, we have customer
> > requests that are requiring us to look at LKCD disk-based dumps as an
> > alternative, co-existing dump mechanism.  Since the two methods are not mutually
> > exclusive, LKCD will never kill off netdump -- nor certainly vice-versa.  We're
> > all just looking for a better means to be able to
> > provide support to our customers, not to mention its value as a
> > development aid.
> >
> > Dave Anderson
> > Red Hat, Inc.

Note that RH, LKCD and CGL agree -- we need more than just dumping
across the network (despite Linus).  What I have as the most succinct
CGL dumping summary is:
- to disk
- across network
- summary (i.e., set specific kernel contents for dumping, to shrink
- minimal disruptive live snapshot (define minimal, but, yeah)
- tools to deal with the above (save, transfer, analyze, etc.)

So why start a *new* net dump project?  RH already has one.  It works (I
assume).  It doesn't seem Linus has accepted that either, has RH not
submitted?  My reading of the posts says that the user community (who
specific, not sure, but some users) need to vouch for whatever dump
technology is to be included.  If the RH user base isn't doing it, I
doubt a new netdump will bring them in anytime soon.

> Steve is proposing a mini crash dump project that has a chance of
> mainline acceptance.  This would be beneficial to DCL, CGL, and the
> community at large.

RH already has a netdump.  Why would this one be more acceptable? 
Non-distro source?  Is NetDump not open?  *NO argument* a useful,
kernel-integrated dump facility would be invaluable to everyone.  Usual
issue breaks down to *how* to get there ;)

> Please give Steve your feedback on this proposal.  I know there has been
> some work going on with network dumps, so if you feel that an existing
> project might be a good baseline for the mini crash dump project, please
> sync up with Steve.

RH netdump.  Don't know URL off hand, but should be easy to find. 
Contact Dave Anderson.

I personally think the most effective path here is to help LKCD and
NetDump find common ground; and get the advocacy machinery going to
document how and why dumping is essential (user feedback Linus wants). 
Not a new 'minimal' netdump project.

> Thanks,
> John
> -----Forwarded Message-----
> > From: Stephen Hemminger <shemminger at osdl.org>
> > To: dcl_tech_board at osdl.org, dcl_steering at osdl.org
> > Subject: [Dcl_tech_board] Linux Kernel Crash Dump (LKCD) evaluation
> > Date: 11 Apr 2003 16:34:52 -0700
> >
> >       Linux Kernel Crash Dump Evaluation
> >
> > <snip>

Peter R. Badovinatz aka 'Wombat' -- IBM Linux Technology Center
preferred: tabmowzo at us.ibm.com / alternate: wombat at us.ibm.com
These are my opinions and absolutely not official opinions of IBM, Corp.

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