How LKCD Works

Linux Crash HOWTO
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# 2. How LKCD Works

When a kernel encounters certain errors it calls the "panic" function which results from a unrecoverable error. This panic results in LKCD initiating a kernel dump where kernel memory is copied out to the pre-designated dump area. The dump device is configured as primary swap by default. The kernel is not completely functional at this point, but there is enough functionality to copy memory to disk. After dump finishes copying memory to disk, the system re-boots. When the system boots back up, it checks for a new crash dump. If a new crash dump is found it is copied from the dump location to the file system, "`/var/log/dump`" directory by default. After copying the image, the system continues to boot normally and forensics can be performed at a later date.

## 2.1. What You Need

`lkcd-kernelxxx.diff` file for patching the kernel. The kernel version supported will change routinely. `lkcdutils-xx.src.rpm` - this is the utilities source and scripts you will need to setup and read a crash. At the time of this writing there is a i386 binary rpm available from lkcd.sourceforge.net, but you will still need the patches for the startup scripts from the source rpm.

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