Kdump service starts too late, so early crashes will have no chance
to get kdump kernel booting, this will cause crash information to be
lost. It is necessary to add a dracut module in order to load crash
kernel and initramfs as early as possible. You can provide "rd.early
kdump" in grub commandline to enable, then the early kdump will load
those files like the normal kdump, which is disabled by default.
For the normal kdump service, it can check whether the early kdump
has loaded the crash kernel and initramfs. It has no conflict with
the early kdump.
If you rebuild the new initramfs for early kdump, the new initramfs
size will become large, because it will put the vmlinuz and kdump
initramfs into the new initramfs.
In addition, early kdump doesn't support fadump.
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Reviewed-by: Kazuhito Hagio <khagio@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
