An "in memory" kernel core dump facility and analysis tool for alpha systems is
available.
This facility produces reliable dumps in a variety of circumstances including
hung systems
(via sysrq key) and faults or panics in thread, interrupt and exception
context. The analyzer,
which is now layered on gdb, provides a rich set of commands for debugging core
files and live
systems. For example stack traces for all kernel threads including the ones
executing at crash
time can be obtained. Exception frames are provided in the stack traces and
parameter values will
be added in the future. The analyzer is designed to facilitate the addition of
custom commands.
We are working on the following items:
1. Support for other architectures. A few Intel systems (HP, Compaq
laptops) will work
with this package, but others (Dell) do not. The issue is
whether the BIOS
allows a reboot without clearing memory. We are working on
this problem.
Soon we will port to architectures other than Intel and
Alpha.
2. Make this code available for the latest development release.
3. Tie the "crash" srm console command into the core dump code. This
will be useful
for machines with halt buttons (Compaq boxes) that are hung,
even at interrupt
level.
The code and instructions are available at
http://www.missioncriticallinux.com/download.
The core dump facility is called "Kernel Core Dump v2.0" and the analysis tool
"Core Analysis Suite v2.0."
While we are working on in-memory dumps for Intel, the following options exist
for Intel today.
1. One can use v1.0 of the Kernel Core Dump (which is disk based)
with v2.0 of the analysis tool.
This version will produce core dumps when the processor
calling panic is
at thread level.
2. One can try the v2.0 Kernel Core Dump. Forcing a crash with
"sysrq c" will result
in a core file for BIOS's that preserve memory.
3. A core dump facility is available from SGI at
http://oss.sgi.com/projects/lkcd/download.
The analysis tool from Mission Critical Linux can read SGI
V1.0 core files. The ability to
read V2.0 SGI files is under test.
-Dave Winchell
-Dave Anderson
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