On 01/09/19 at 03:38pm, Kazuhito Hagio wrote:
Since early kdump is generally used for capturing vmcore when
boot-time panic occurs, if a system always reboots after capturing
vmcore, it can go into a crash loop.
To avoid this issue, this patch add a note on 'final_action' option
to the early kdump document.
Signed-off-by: Kazuhito Hagio <k-hagio(a)ab.jp.nec.com>
Cc: Dave Young <dyoung(a)redhat.com>
Cc: Lianbo Jiang <lijiang(a)redhat.com>
early-kdump-howto.txt | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/early-kdump-howto.txt b/early-kdump-howto.txt
index fe4f13f..6da6220 100644
@@ -1,6 +1,7 @@
Early Kdump HOWTO
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
@@ -12,7 +13,8 @@ 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.
-How to configure early kdump:
+How to configure early kdump
We assume if you're reading this document, you should already have kexec-tools
@@ -21,6 +23,14 @@ You can rebuild the initramfs with earlykdump support with below
1. start kdump service to make sure kdump initramfs is created.
# systemctl start kdump
+ NOTE: If a crash occurs during boot process, early kdump captures a vmcore
+ and reboot the system by default, so the system might go into crash loop.
+ You can avoid such a crash loop by adding the following settings, which
+ power off the system after dump capturing, to kdump.conf in advance:
+ final_action poweroff
+ default poweroff
'default' can be anything other than "reboot", so it would be better to
describe it here.
2. rebuild system initramfs with earlykdump support.
# dracut --add earlykdump
@@ -50,5 +60,6 @@ kdump kernel
Mar 09 10:02:47 localhost.localdomain dracut-cmdline: early-kdump is disabled.
At present, early kdump doesn't support fadump.