A couple of days ago I submitted a question about compressed dumps and
disabling of them.
I would like to thank the following who responded:
Dr. Tom Blinn, 603-884-0646 [tpb_at_doctor.zk3.dec.com]
alan_at_nabeth.cxo.dec.com
Who both basically said the same thing. I have attached Dr Tom's summary
for your information.
Having spoken to the guy who wrote the original documentation, it appears
that there was some problem with the analysis of compressed dumps when it
was first introduced - hence disabling it.
This is certainly not an issue now. We don't disable this internally
anymore. I am going to remove it from the docs.
Many thanks for your help.
Regards - Tony
Quotation: "Is the glass half full or half empty?? ...
Well, drink it anyhow, that's what I say".
Pete Goss.
+-----------------------------------------------------------------+
| TONY MILLER - Systems Projects - VODAFONE LTD, Derby House, |
| Newbury Business Park, Newbury, Berkshire. |
+-------------+---------------------------------------------------+
| Phone | 01635-507687(local) |
| Work email | ANTHONY.MILLER_at_VF.VODAFONE.CO.UK |
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Disclaimer: Opinions expressed in this mail are my own and do not
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> I have 3 questions:
>
> 1. What is compressed dump? Is this something along the lines of the -C
> switch within vdump??
>
> 2. Why would I want to disable this feature? Was this a known problem in
> an earlier release of DUNIX/TRUcluster software?
>
> 3. Should I disable this again??
You should be able to find information on compressed kernel dumps in both
the
release notes for the version in which it was first introduced (I can't
recall
off the top of my head whether it was in V4.0B or V4.0D, but V4.0D seems
like
the right version), as well as in the reference pages for things like
crashdc
(well, I just checked, and that reference page hasn't been updated yet), but
I
do find information on it in the savecore(8) reference page (q.v.) for
V4.0D.
The crash dump contains the contents of a portion of physical memory (or
all of physical memory in the case of a full crash dump) at the time of
the
crash. The savecore command saves this information in the file vmzcore.n
for a compressed dump, or vmcore.n for an uncompressed dump. Compressed
dumps are produced by default and detected automatically by savecore.
Compression can be disabled if required and either file type can be read
by
savecore.
I have no idea why you would want to disable this feature. You need to ask
the person who wrote the document why they thought you should disable it at
your site. Maybe it was buggy in an older release, I don't know.
You should only change the system defaults when you KNOW why you are doing
so. Saving compressed core files is the default behaviour; as far as I know
there are no known problems with this facility, we use it all the time here
in the UNIX development environment, including on our production clusters,
and it's the default on most installed customer systems.
Tom
Dr. Thomas P. Blinn + UNIX Software Group + Compaq Computer Corporation
110 Spit Brook Road, MS ZKO3-2/W17 Nashua, New Hampshire 03062-2698
Technology Partnership Engineering Phone: (603) 884-0646
Internet: tpb_at_zk3.dec.com Digital's Easynet: alpha::tpb
ACM Member: tpblinn_at_acm.org PC_at_Home: tom_at_felines.mv.net
Worry kills more people than work because more people worry than work.
Keep your stick on the ice. -- Steve Smith ("Red Green")
My favorite palindrome is: Satan, oscillate my metallic sonatas.
-- Phil Agre, pagre_at_ucsd.edu
Yesterday it worked / Today it is not working / UNIX is like that
-- apologies to Margaret Segall
Opinions expressed herein are my own, and do not necessarily represent
those of my employer or anyone else, living or dead, real or imagined.
Received on Thu Jul 29 1999 - 09:05:05 NZST