Thiruvengada Govindan wrote:
>
> Hi,
> A possibly useful feature would be for the Linux KDB to support a
> command to initiate a system dump (i haven't looked at the latest
> version though so please excuse if this is already supported). A lot of
> times when a system appears hung doing an insmod would just not be
> feasible and rather than tweak the kernel to panic and thereby force the
> system to dump it may just be better for KDB itself to support say a
> "sysdump" command that would take a dump of the system image before
> reboot.
>
> Also how about having a "live dump" feature for Linux ?? If testing lkcd
> is all that you want to do then why go all over panic'ing and dumping
> the system why not just do a live dump of the system to the dump device
> and use the saved dump.
There is a 'livedump' command in lcrash. It runs through all memory pages and
dumps them in the same format that the system uses (compressed). Of course
this won't test the kernel mechanisms for dumping core. From a kernel point
of view, the real challenge is having things work when there HAS been a panic.
That is when you would most expect normal behavior to have problems. Having
a live dump facility in the kernel would not address this level of testing.
BTW, the only thing you can't do with the livedump from lcrash is analyze the
running task (lcrash itself), obviously.
Thanks,
Tom
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