README

kdump-estimate
----------

This is for RHEL/fedora kexec-tools test only!

1. What is this?
   This script will reboot current system and trigger a panic to estimate real
   kdump memory usage. 

2. How it works?

   1) This script will create a hard link for currently running kernel, and
   will create a grub entry named "kdump-estimate". Then it will update kernel
   commandline args crashkernel to a bigger number(1/4 of the system RAM, up
   to 16GB). The next boot will be set to it by grub-reboot.

   2) Create kdump-estimate.service for trigger a panic and collect kdump logs
   on booting. Create kdump-esimate-cleanup.service for cleaning grub entries
   and other temporary files.

   3) Rebuild kdump initramfs with rd.memdebug=4, then trigger a panic.

   4) The result will be saved in /var/kdump/kdump-estimate.

3. How to use?

   1) You can clone this repo or just copy this script and run it:
   ```
   # ./kdump-estimate estimate
   ```

   2) Wait a while, it may take long time because it needs reboot system twice.

   3) Login the system and check the report:
   ```
   # ./kdump-estimate report
   ```

4. Limitation

   1) Only tested on X86_64.

   2) Only support fs, nfs and ssh as dump target.

   3) Grubby is required.