Debugging a production server?

Greg 'groggy' Lehey grog at
Wed Jun 30 17:29:55 PDT 2004

On Thursday,  1 July 2004 at  2:14:20 +0200, Daniel Eriksson wrote:
> What can I do to optimize my debugging ability on a production server (where
> no slowdown during normal operation is acceptable)? Will compiling the
> kernel with debug symbols and DDB cause any performance degradation?

No.  The symbols don't get loaded.  ddb will cause extreme performance
degradation if you enter the debugger, of course, but that's obvious.

> Any other options I should consider?

Nothing occurs to me offhand.  A lot depends on the kind of debugging
you want to do.  Not everything requires kernel options.

> The goal is to be able to do some simple investigation myself and
> write fully detailed PRs.

If you've been experiencing particular kinds of problems, it might be
worth mentioning them here.

> Also, how clever is the core dumping code? Will it be able to handle
> swap spread out over two discs (as long as total size is larger than
> my RAM)?


> If not, what about a situation where there's three swap areas, but
> only one of them is bigger than the RAM?

That's fine.  Dump to the big partition.

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